Spigot Plugin Error?

Can someone help me? I'm trying to learn to program Minecraft plugins, but I can't get any further.

It's probably because you:

CommandSender commandSender

And not:

CommandSender sender

wrote.

You can also use color codes without any problems. E.g. §4 for red. That saves you some effort and you can even get more variation in return.

Unfortunately, it's not because of that. There are still four error messages where it says Not annotated parameter overrides @NotNull parameter

If you can't even read error messages, you should get this programmed.

Obviously the error lies in your main class and not in your command.

You seem to have no idea of the basics of Java let alone object orientation.

Learn these first before you try to assemble something on the off chance.

No, that's certainly not the reason

It is definitely up to the Main.java, you could post a screenshot of it, or the best thing to do is to write to Hekates # 2298 via Discord