How to cap a copper water line to a fridge without turning off water valve

I’m in kind of a difficult situation, I’m moving out of my old apartment and I need to get the fridge out but there is no water shutoff valve in any of the units in my complex. It’s an older building and I have to request a water shutoff from the HOA 24 hours in advance because it shuts off the water for the whole floor. The problem is that because of Covid, I can’t get a hold of maintenance and there is no one in the office. I’ve been trying to get this taken care of for months to no avail. Is there any way to stop the flow of water without shutting off the valve so I can cap the line and get the fridge out of here? Any help would be immensely appreciated, I’m a total noob when it comes to these things.