DOES NOT WORK ON SPIGOT OR PAPER OR THERE FORKS

(download the zip, unzip the zip and put the jar file into the minecraft mods folder) contact me on discord if you need help @0benJ ᶠᵃˣᴴᵃˣ#5226

use the .jar file with 1.16.5 fabric, put the jar file within the mods folder and start fabric on the Minecraft launcher, load into a game
(works on single player, vanilla servers, fabric servers) get the items you want to dupe leave the game and join back now put items into a 
chest and hold a book and quil and type .d in the chat it will disconnect you, join back and the items will be in your inventory and chest,
repeat as many times as you want.