My parking space has an old sliding vertical metal door. The motorized unit has been broken for ages and the door is permanently left open - I am fine with this since the front of my car protrudes from the entrance anyway. Above the entrance, there is some sheet metal paneling that has come loose (photos attached). From what I can see, the top part was originally fixed with some type of sealant, the bottom part does not fit very snugly.

What would be the easiest way to get this fixed? As you can see, I have currently just applied some tape. I am fairly useless with these situations, so any advice much appreciated!