If Skript is installed, you have the option to add a LootSkriptEvent to any given LootSet. Following the videos below to normally add a new loot, do this for the LootSkriptEvent, and input the tag of the
on loot event you want to trigger.
Example Skript:
Code (Text):
on loot "troll":
send "Haha you got trolololed" to player
You can also give a crate to a player:
Code (Text):
command /cratesk <string>:
trigger:
give crate arg-1 to the player
And list all loaded crates:
Code (Text):
command /crateslist:
trigger:
loop crates: # note*: 'crates' is a string list
send "Crate %loop-value%" to player