You need to change your 'config.yml' file. (Optional)
Features and Enhancements:
+Added:
gamemode: <mode> command - Set gamemode for players
(CREATIVE, SURVIVAL, ADVENTURE, SPECTATOR).
+Added:
send: <message> command - Send a message in chat from the player.
+Added:
give_potion_effect: <effect> command - Give a potion effect to the player.
+Added:
remove_potion_effect: <effect> command - Remove a potion effect from the player.
This update introduces new commands 'gamemode', 'send', 'give_potion_effect', and 'remove_potion_effect' for player join and quit actions.