It’s a bit tricky to tell from the photo but you should be able to solder this connection back together again.
Soldering is relatively simple, but you’ll need a soldering iron, and some solder to do it. You’ll also want to cut back the wrapping on the wire as to make sure you can get a good amount of wire. As an alternative you could also buy a cheap wire connector and just splice the two sides together… this isn’t a great way to fix this issue though.