java.lang.NoSuchMethodError: No such DSL method 'ci' found among steps when using jenkins shared library

I am using jenkins shared library to build my project, this is my shared library directory structure:

this is my ci.groovy call method:

#!groovy
def call(String type,Map map) {
    if (type == "maven") {
    }
}

then using the shared library in my project's jenkins file liket this:

#!groovy
library 'pipeline-shared-library'
    def map = [:]
    map.put('repoBranch','master')
    
ci("maven",map)

but when I build this project(I already add shared library in jenkins system config), the logs output like this:

[Pipeline] End of Pipeline
java.lang.NoSuchMethodError: No such DSL method 'ci' found among steps [VersionNumber, acceptGitLabMR, addGitLabMRComment, archive, bat, build, catchError, checkout, deleteDir, dir, dockerFingerprintFrom, dockerFingerprintRun, echo, emailext, emailextrecipients, envVarsForTool, error, fileExists, getContext, git, gitlabBuilds, gitlabCommitStatus, input, isUnix, jiraComment, jiraIssueSelector, jiraSearch, junit, library, libraryResource, load, lock, mail, milestone, node, parallel, powershell, properties, publishHTML, pwd, pwsh, readFile, readTrusted, resolveScm, retry, script, sh, sleep, stage, stash, step, svn, timeout, timestamps, tm, tool, unarchive, unstable, unstash, updateGitlabCommitStatus, validateDeclarativePipeline, waitUntil, warnError, withContext, withCredentials, withDockerContainer, withDockerRegistry, withDockerServer, withEnv, wrap, writeFile, ws] or symbols [all, allBranchesSame, allOf, always, ant, antFromApache, antOutcome, antTarget, any, anyOf, apiToken, architecture, archiveArtifacts, artifactManager, authorizationMatrix, batchFile, bitbucket, bitbucketBranchDiscovery, bitbucketForkDiscovery, bitbucketPublicRepoPullRequestFilter, bitbucketPullRequestDiscovery, bitbucketSshCheckout, bitbucketTagDiscovery, bitbucketTrustEveryone, bitbucketTrustNobody, bitbucketTrustProject, bitbucketTrustTeam, bitbucketWebhookConfiguration, bitbucketWebhookRegistration, booleanParam, branch, brokenBuildSuspects, brokenTestsSuspects, buildButton, buildDiscarder, buildRetention, buildingTag, caseInsensitive, caseSensitive, certificate, changeRequest, changelog, changeset, checkoutToSubdirectory, choice, choiceParam, cleanWs, clock, cloud, command, credentials, cron, crumb, culprits, defaultFolderConfiguration, defaultView, demand, developers, disableConcurrentBuilds, disableResume, docker, dockerCert, dockerfile, downloadSettings, downstream, dumb, durabilityHint, envVars, environment, equals, exportIpa, expression, extendedChoice, file, fileParam, filePath, fingerprint, frameOptions, freeStyle, freeStyleJob, fromScm, fromSource, git, gitBranchDiscovery, gitHubBranchDiscovery, gitHubBranchHeadAuthority, gitHubExcludeArchivedRepositories, gitHubForkDiscovery, gitHubPullRequestDiscovery, gitHubSshCheckout, gitHubTagDiscovery, gitHubTopicsFilter, gitHubTrustContributors, gitHubTrustEveryone, gitHubTrustNobody, gitHubTrustPermissions, gitLabConnection, gitTagDiscovery, github, githubPush, gitlab, gradle, headRegexFilter, headWildcardFilter, hyperlink, hyperlinkToModels, importDeveloperProfile, inheriting, inheritingGlobal, installSource, isRestartedRun, jdk, jdkInstaller, jgit, jgitapache, jnlp, jobName, label, lastDuration, lastFailure, lastGrantedAuthorities, lastStable, lastSuccess, legacy, legacySCM, list, local, location, logRotator, loggedInUsersCanDoAnything, mailer, masterBuild, maven, maven3Mojos, mavenErrors, mavenMojos, mavenWarnings, modernSCM, myView, namedBranchesDifferent, newContainerPerStage, node, nodeProperties, nonInheriting, none, not, overrideIndexTriggers, paneStatus, parallelsAlwaysFailFast, parameters, password, pattern, permanent, pipeline-model, pipeline-model-docker, pipelineTriggers, plainText, plugin, pollSCM, preserveStashes, projectNamingStrategy, proxy, queueItemAuthenticator, quietPeriod, rateLimit, rateLimitBuilds, recipients, requestor, run, runParam, sSHLauncher, schedule, scmRetryCount, scriptApproval, scriptApprovalLink, search, security, shell, skipDefaultCheckout, skipStagesAfterUnstable, slave, sourceRegexFilter, sourceWildcardFilter, ssh, sshUserPrivateKey, stackTrace, standard, status, string, stringParam, suppressAutomaticTriggering, swapSpace, tag, teamSlugFilter, text, textParam, tmpSpace, toolLocation, triggeredBy, unlockMacOSKeychain, unsecured, untrusted, upstream, upstreamDevelopers, userSeed, usernameColonPassword, usernamePassword, viewsTabBar, weather, withAnt, xcode, xcodeBuild, zfs, zip] or globals [currentBuild, deploy, docker, env, params, pipeline, scm]
at org.jenkinsci.plugins.workflow.cps.DSL.invokeMethod(DSL.java:202)
at org.jenkinsci.plugins.workflow.cps.CpsScript.invokeMethod(CpsScript.java:122)
at sun.reflect.GeneratedMethodAccessor630.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1213)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1022)
at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:42)
at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:113)
at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:163)
at org.kohsuke.groovy.sandbox.GroovyInterceptor.onMethodCall(GroovyInterceptor.java:23)
at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onMethodCall(SandboxInterceptor.java:157)
at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onMethodCall(SandboxInterceptor.java:142)
at org.kohsuke.groovy.sandbox.impl.Checker$1.call(Checker.java:161)
at org.kohsuke.groovy.sandbox.impl.Checker.checkedCall(Checker.java:165)
at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.methodCall(SandboxInvoker.java:17)
at WorkflowScript.run(WorkflowScript:33)
at ___cps.transform___(Native Method)
at com.cloudbees.groovy.cps.impl.ContinuationGroup.methodCall(ContinuationGroup.java:86)
at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.dispatchOrArg(FunctionCallBlock.java:113)
at com.cloudbees.groovy.cps.impl.FunctionCallBlock$ContinuationImpl.fixArg(FunctionCallBlock.java:83)
at sun.reflect.GeneratedMethodAccessor354.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
at com.cloudbees.groovy.cps.impl.LocalVariableBlock$LocalVariable.get(LocalVariableBlock.java:39)
at com.cloudbees.groovy.cps.LValueBlock$GetAdapter.receive(LValueBlock.java:30)
at com.cloudbees.groovy.cps.impl.LocalVariableBlock.evalLValue(LocalVariableBlock.java:28)
at com.cloudbees.groovy.cps.LValueBlock$BlockImpl.eval(LValueBlock.java:55)
at com.cloudbees.groovy.cps.LValueBlock.eval(LValueBlock.java:16)
at com.cloudbees.groovy.cps.Next.step(Next.java:83)
at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:174)
at com.cloudbees.groovy.cps.Continuable$1.call(Continuable.java:163)
at org.codehaus.groovy.runtime.GroovyCategorySupport$ThreadCategoryInfo.use(GroovyCategorySupport.java:129)
at org.codehaus.groovy.runtime.GroovyCategorySupport.use(GroovyCategorySupport.java:268)
at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:163)
at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$001(SandboxContinuable.java:18)
at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:51)
at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:185)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:400)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$400(CpsThreadGroup.java:96)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:312)
at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:276)
at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:67)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:131)
at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
at jenkins.security.ImpersonatingExecutorService$1.run(ImpersonatingExecutorService.java:59)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Finished: FAILURE

Am I missing something? what should I do to fix this?

Generally vars directory hosts script files that are exposed as a variable in Pipelines.

If you move your ci.groovy to 'vars' directory it should work.