devtrackers.gg
i cannot see what you are referring to i am afraid. when i click backpack it opens the pictures tab, which shows me to not be wearing a backpack.
The backpack on there is cosmetic and can have additional buffs, but your inventory is separate from it, you always have it, no matter if you wear a backpack or not. Indeed just move the whole UI window to the left, then you'll see it again.