I live in the top floor of a 3 floor apartment. The bottom is the garages, then my neighbour, then us on top. I need to get a connection to the garage, but have zero access to the middle floor as it's not ours. We are also renting so running cables somehow is out of the question.

I have power in the garage, but I'm not 100% sure how it's connected to our power so I don't know if a powerline connector would work (if at all). WiFi is fine and it does not need to be a fast connection, just fast enough for a webcam. I'll be putting a 3D printer in the garage, with octoprint and a webcam on a raspberry pi. I'm not sure if an extender would work (again it doesn't need to be a super fast connection), or if I should try powerline or if something else exists that I'm not aware of.

I am using a Frtizbox 7490. I took my phone down, and I get about a half bar connection on the wifi, which wont' let me browse sites or the network, it's just too low of a connection.

I'm not able to move the router as that's where the fibre connection is, and the apartment isn't wired for ethernet.

An awesome mspaint drawing to explain better:

Any help or suggestions would be greatly appreciated. Cheers.