Help making custom backpack for character

[CottonDoodles]

I'm trying to create a custom backpack for this character, and I want the backpack to show up in their inventory when they spawn in. I've gotten other custom items to work (made a custom weapon), but I can't seem to get the backpack working. whenever I try to spawn into the world, I get this error:

Quote

[string "scripts/components/inventory.lua"]:637: attempt to index local 'inst' (a nil value) LUA ERROR stack traceback: scripts/components/inventory.lua:637 in (method) GiveItem (Lua) <636-769>
scripts/prefabs/player_common.lua:1941 in (method) OnNewSpawn (Lua) <1937-1949>
scripts/networking.lua:250 in () ? (Lua) <238-256>
=[C]:-1 in (method) SendSpawnRequestToServer (C) <-1--1>
scripts/mainfunctions.lua:1289 in (local) cb (Lua) <1287-1290>
scripts/frontend.lua:538 in (method) DoFadingUpdate (Lua) <502-542>
scripts/frontend.lua:590 in (method) Update (Lua) <550-707>
scripts/update.lua:92 in () ? (Lua) <33-129>

any help would be much appreciated