alright after hours of messing around with it im completely stuck with this i've tried everything i can think of from changing the name of the container to different ways of typing out the name in the .lang fil and i can't seem to get it
After checking the main game's english file and testing it out, I found the right one.
The name of the key in the container is KeyStudy.
so, it's:
<CATEGORY Name="Inventory">
<Entry Name="ItemName_KeyStudy">Key name</Entry>
<Entry Name="ItemDesc_KeyStudy">Key Description</Entry>
</CATEGORY>