It does what it says on the can.
I could not find a mod like this for Fabric or Java 1.21.1, so I decided to throw one together myself. The inventory locking mechanic can be toggled with the command:
/gamerule hotbarOnly true/false
Do note, there is a bug where the inventory slots remain red after toggling off, but if you toggle on and off again, it should clear up. Otherwise, the bug is purely cosmetic.
I do not plan on porting this mod to newer versions or alternative mod loaders. If you want that, you are more that welcome to extract my mod and do it yourself.
Enjoy!
-JBR (MissMixOinky)
