Download needed things:

• Java (Required to run Minecraft.)
• IntelliJ (The program you are going to code on, recommended community edition.)
• Spigot Library API (Select and download the version of the spigot server you want to open.)
  • Paper MC (For a better performance Minecraft server. Recommended.)

Install all required plugins on the first launch.

Choose Plugins ➜ search Minecraft Development install it. You can find a lot of helpful plugins here.

Create a new project. On the menu page, choose New Project.

On the New Project menu, choose Minecraft ➜ Spigot Plugin ➜ click next.

Set up new project detail.

Choose the Minecraft version you want to code. Choose the location where your project going to save and you are good to go here.

Set up the build artifact.

• Pressing Crtl + Alt + Shift + S or File ➜ Project Structure.
• The menu will pop in and you need to go to the Artifacts section ➜ Add ➜ Jar ➜ From modules with dependencies and click Ok.

• In the Output directory, you going to choose the location where the jar file will export and check Include in project build and click Apply.

• Build the artifact by Build ➜ Build artifacts...

• Or you can change the hotkey by following this or pressing the hammer button here.

And now you are basically done with the first setup of your IntelliJ IDEA to code a plugin on.