Because Modrinth will only add a plugin category in the future.
I am currently uploading the plugin to Modrinth, yes, but the Paper plugin is tagged as a Fabric mod.
I won't upload to spigotmc as it has no Gradle integration and I don't want to support the site nor the community.
So Crazytigerbw you have to use the Fabric or Forge mod on this platform at the moment.