looking for an expert in firebase. need help with backend stuff for a flutter app. [ setting up friendlisht]

hello, I am looking for an expert in firebase. I am working on a flutter app. that lets users log in using google auth. then the user can text and send audio to their friends. while I have the front end ready and it sends a message to firebase. i need someone to help me set up the backend so that I can get a friend list, who I can text.