Speculation I Found This Untradable Item

I was doing the hunger of gerts quest line, and while I was wandering around the gert fort for easter eggs, I found an untradable item called "Library key" it has the same texture as the broken key.
If you want to get one yourself, go to the big fort where Chief Lobo is and then go to the watch tower attached to it.

 

This item is already known. You can use it to enter the secret room in the library.
You can find it here: https://map.wynncraft.com/#/-36/64/-5400/max/0/0
Unfortunately we don't know if it's ??? relevated or not, because some people say that there is a second secret room.