Minecraft plugin load failed: java.lang.IllegalArgumentException

I made a basic 1.19 plugin using spigot, and load it with paper. But it says load fail. This is the exception:

[20:50:56 ERROR]: [DirectoryProviderSource] Error loading plugin: File 'plugins\Real_Craft.jar' failed to load!
java.lang.RuntimeException: File 'plugins\Real_Craft.jar' failed to load!
        at io.papermc.paper.plugin.provider.source.FileProviderSource.registerProviders(FileProviderSource.java:59) ~[paper-1.19.4.jar:git-Paper-483]
        at io.papermc.paper.plugin.provider.source.DirectoryProviderSource.lambda$registerProviders$2(DirectoryProviderSource.java:32) ~[paper-1.19.4.jar:git-Paper-483]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) ~[?:?]
        at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179) ~[?:?]
        at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[?:?]
        at java.util.Iterator.forEachRemaining(Iterator.java:133) ~[?:?]
        at java.util.Spliterators$IteratorSpliterator.forEachRemaining(Spliterators.java:1845) ~[?:?]
        at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[?:?]
        at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) ~[?:?]
        at java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) ~[?:?]
        at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[?:?]
        at java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[?:?]
        at io.papermc.paper.plugin.provider.source.DirectoryProviderSource.registerProviders(DirectoryProviderSource.java:30) ~[paper-1.19.4.jar:git-Paper-483]
        at io.papermc.paper.plugin.provider.source.DirectoryProviderSource.registerProviders(DirectoryProviderSource.java:14) ~[paper-1.19.4.jar:git-Paper-483]
        at io.papermc.paper.plugin.util.EntrypointUtil.registerProvidersFromSource(EntrypointUtil.java:14) ~[paper-1.19.4.jar:git-Paper-483]
        at io.papermc.paper.plugin.PluginInitializerManager.load(PluginInitializerManager.java:100) ~[paper-1.19.4.jar:git-Paper-483]
        at net.minecraft.server.Main.main(Main.java:126) ~[paper-1.19.4.jar:git-Paper-483]
        at org.bukkit.craftbukkit.Main.main(Main.java:309) ~[paper-1.19.4.jar:git-Paper-483]
        at io.papermc.paperclip.Paperclip.lambda$main$0(Paperclip.java:42) ~[app:?]
        at java.lang.Thread.run(Thread.java:833) ~[?:?]
Caused by: java.lang.IllegalArgumentException: File 'plugins\Real_Craft.jar' is not a valid plugin file, cannot load a plugin from it!
        at io.papermc.paper.plugin.provider.source.FileProviderSource.registerProviders(FileProviderSource.java:54) ~[paper-1.19.4.jar:git-Paper-483]
        ... 20 more

I tried to fix it from some ways to fix it, the tutorial I followed is https://www.youtube.com/watch?v=WcFb0GO14zY, and I can't find errors in my code. here's my plugin.yml and main script

name: RealCraft
version: 1.0.0
author: knowscratcher
main: com.knowscratcher.realcraft.RealCraft
api-version: 1.19

and my main script is

package com.knowscratcher.realcraft;

import org.bukkit.ChatColor;
import org.bukkit.plugin.java.JavaPlugin;

public class RealCraft extends JavaPlugin {

    @Override
    public void onEnable() {
        getServer().getConsoleSender().sendMessage(ChatColor.LIGHT_PURPLE+"[RealCraft]:Plugin is enabled");
    }

    @Override
    public void onDisable() {
        getServer().getConsoleSender().sendMessage(ChatColor.RED+"[RealCraft]:Plugin is disabled");
    }

}

If the plugin.yml file isn't on the jar, bukkit, spigot and paper cannot load the plugin. You need to make sure to include it in the final jar. You can do it manually, but I don't recommend it.

You should use a project manager to make the plugin.yml automatically included.

Here you can see an example of an extremely simple plugin that uses Maven: https://github.com/OnyxianSoul/SendConsoleMessage .

If you set up your folder structure and pom.xml in the same way, and use maven to build your jar, your plugin jar will include the necessairy files, and will be loaded correctly.

Good luck

Try using the Minecraft Development plugin on Intellij, it sets up the workspace. According to your error it seems like your plugin doesn't contain the files for it to be properly recognized. https://plugins.jetbrains.com/plugin/8327-minecraft-development
It's also just a lot easier to use in general.