How to use a key?

[Spaceowl]

Hello, I started the game today. The first room is locked due copyright issues. So I started the second.
Found a key and want to open the desk with it. But can't I threw the key away or nothing happens. I tried using every key on keyboard.
Here in this vieo you can see how the cursor moves. Bu my cursor doesn't move at all! :( What I'm doing wrong?
https://youtu.be/Uh7pZCu-qZI?feature=shared&t=130

Also I have a RTX 4080, play on 2560x1440, have 110 fps (locked at 110), smooth frametime. But the game is stuttering or lagging terrible, why is this?

[Olipool]

You picked up the wrong key, the one you have to use is on the window board :)

And the lagging of the game is because of poor optimization, it is my first game, so sorry for that :(