If you’d like to request a copy of data that was posted to an account impersonating you, you should first contact a lawyer or your local law enforcement agency and discuss this issue with them.

If you decide to pursue legal action, we recommend having the lawyer or officer review Facebook operational guidelines and contact them by following the directions listed there. Once they contact Facebook, Facebook will be able to communicate with them regarding this issue. Please be aware that there are situations where Facebook may be unable to retrieve the information you have requested due to technical limitations.

Learn how to report an account that is impersonating you.

Source: https://www.facebook.com/help/202993146405258?helpref=uf_permalink