Actions are defined in the config for hotbar or menu items like this:
hotbar: items:hide-players: item: name: "&b&lHide Players &7(Right-Click)" lore: - "&fRight-click to hide players" material: INK_SACK amount: 1slot: 0 actions: - "[command] hide" <-- THIS IS AN ACTION, THIS IS ALSO OUND ON MENU ITEMS
A list of actions:
Hotbar-and-menu-item-actions:[command] warp test <-- COMMAND EXECUTED BY PLAYER[console] kill %player% <-- COMMAND EXECUTED BY CONSOLE[message] Hello %player% <-- RAW MESSAGE SENT TO PLAYER[close] <-- CLOSE AMENU[menu] sub-selector <-- LET PLAYER OPEN THE MENU CALLED sub-selectorHotbar-only-actions:[enderbutt] <-- FLY ON AN ENDERPEARL!![endertp] <-- GET LAUNCHED WITHOUT RIDING AN ENDERPEARL[paintball] <-- SHOOT SNOWBALL THAT VANISHES PLAYERS FOR 10 SECONDS