Can I use the Default Skeleton of UE and use it as skeleton of my custom made character?

Guys So I’m done creating my character in Zbrush, and I bought a simple animation in market place and I can play that animation in default third person character, so if I create a new skeleton it need to be exact as the default third person character to use that animations too right? now, without creating new skeleton how can I use that animation for my Custom made character? can I use the default skeleton? how? Please I’m frustrated and I can’t find a proper tutorial regarding this matter, all I can see is that they created a new skeleton and animate it, but I got animations ready. I hope someone can help me.