They're floating items, which if you click them will do a specific action, like send a message, run a command, etc.
Plugin Link:
https://www.spigotmc.org/resources/tdg-create-your-own-3d-guis.61903/
They're floating items, which if you click them will do a specific action, like send a message, run a command, etc.
Plugin Link:
https://www.spigotmc.org/resources/tdg-create-your-own-3d-guis.61903/