Here is a very simple mod.
It adds several Crates and keys.
not craftable
[8 Crates]
-Nostalgic (the old HG crates)
-Old (basic texture)
-Rarity (common -> Legendary +vote)
[15 Keys]
-5 Rarity (C->L+V)
-Special Key (funny name)
-Invisible Key
-7 classic Keys (bronze -> emerald)
crates operate under percentage (60,30,10,1)
If you land on 60% you will get one of 4 items (all equally) and use the number of items in the Key area.
Same for others
Only editable in creative mode.
Only opens with the keys if you are not in creative mode.
Only the item and its name are considered for the key and you can choose how many keys it takes to get an item.
simple example:
key = 6 apple "the good one"
you use 6 apples named "the good one" you get 30% and obtain one of three possible items (same quantity)
You can found the mod on curseforge
https://www.curseforge.com/minecraft/mc-mods/aiycrates
Aiycrates add some crates and keys.
[8 Crates]
-Nostalgic (the old HG crates)
-Old (basic texture)
-Rarity (common -> Legendary +vote)
[15 Keys]
-5 Rarity (C->L+V)
-Special Key (funny name)
-Invisible Key
-7 classic Keys (bronze -> emerald)