400 Bad request when generating the Google API access token using Go iamcredentials client API

I am trying to implement iamcredentials Go API client to generate an Access Token to access some Google APIs via REST API, I am using this code

    package main

    import (
    	"context"
    	"log"

    	"google.golang.org/api/iamcredentials/v1"
    )

    func main() {
    	iamcredentialsService, err := iamcredentials.NewService(context.Background())
    	if err != nil {
    		log.Println("error initialize iamcredential Service ", err)
    		return
    	}
    	accessTokenCall := iamcredentialsService.Projects.ServiceAccounts.GenerateAccessToken(
    		"projects/-/serviceAccounts/some-sa@some-project-id.iam.gserviceaccount.com:generateAccessToken",
    		&iamcredentials.GenerateAccessTokenRequest{
    			Scope: []string{
    				iamcredentials.CloudPlatformScope,
    			},
    		},
    	)

    	iamResp, err := accessTokenCall.Do()
    	if err != nil {
    		log.Println("error generate access token", err)
    		return
    	}

    	log.Println(iamResp)
    }

But when I tried to run the above snippet, I got this message

go run main.go 

error generate access token googleapi: Error 400: Request contains an invalid argument., badRequest

Is there any way to check which one is causing the above response? I am not sure since there isn't any good example of implementation. Any help would be appreciated, Thanks.

Notes :

• I have checked following documentation on this topic https://cloud.google.com/iam/docs/creating-short-lived-service-account-credentials and this https://pkg.go.dev/google.golang.org/api/iamcredentials/v1#pkg-overview
• I have already setup the Service account using Service Account Token Creator role on IAM and also enabled the IAM API from the console
• Also I have added GOOGLE_APPLICATION_CREDENTIALS to the environment variables as suggested

@DanielFarrell is right, you need to remove the :generateAccessToken at the end. Here the documentation in the code. Don't hesitate to explore it, it's open source

// GenerateAccessToken: Generates an OAuth 2.0 access token for a
// service account.
//
// - name: The resource name of the service account for which the
//   credentials are requested, in the following format:
//   `projects/-/serviceAccounts/{ACCOUNT_EMAIL_OR_UNIQUEID}`. The `-`
//   wildcard character is required; replacing it with a project ID is
//   invalid.
func (r *ProjectsServiceAccountsService) GenerateAccessToken(name string, generateaccesstokenrequest *GenerateAccessTokenRequest) *ProjectsServiceAccountsGenerateAccessTokenCall {
	c := &ProjectsServiceAccountsGenerateAccessTokenCall{s: r.s, urlParams_: make(gensupport.URLParams)}
	c.name = name
	c.generateaccesstokenrequest = generateaccesstokenrequest
	return c
}