My 240sx s14 gas tank leaks!! Need Help

[josen23]

Hi guys, this is my first post, so don't really know how this works but I'be been having issues with my fuel tank leaking. Dropped it last night and it is leaking from the top of the tank. I've included a picture to show where exactly it leaks from. I have no idea what that part is called so I can get a replacement or just buy an o-ring or sealant for it cause that's where the leak is coming from.