Facebook Account Hacked After Selling Android Phone

I am writing about a serious problem regarding a Facebook account that has been taken over by someone else after my brother sold his Android phone without resetting it. The buyer of the phone gained access to his Facebook account and changed everything, and since then we have not been able to log in or control the account. This situation has been ongoing for about one month. The hacked account is a Facebook gaming account that used to be named “TSP GAMING” and was created around the year 2020. We do not have access to the phone or login details anymore, and at the moment we only remember the UID of the account. We are located in India and we are trying to access Facebook from an Android device, but we have not yet tried recovery steps such as “Forgot password” or sending an ID because we do not know how to proceed in this situation. Our clear request from Facebook is to help us recover access to this Facebook account that was taken over after the phone was sold. We kindly ask you to use the UID, the old profile name “TSP GAMING” and the creation year information to identify the account and guide us through the steps needed so that my brother can safely regain control of his account.