I have used this function for Facebook Login in Flutter.
Check the below code.
The plugin i used is flutter_facebook_auth: ^3.4.0.
Future<void> facebookLogin(){
final result = await FacebookAuth.instance
.login(permissions: ["email", "public_profile"]);
if (result.status == LoginStatus.success) {
final OAuthCredential credential =
FacebookAuthProvider.credential(result.accessToken.token);
final userObj = await FirebaseAuth.instance
.signInWithCredential(credential);
print("Facebook Data with Credentials -> ${userObj.user.toString()}");
final email = userObj.user.providerData[0].email;
final displayName = userObj.user.providerData[0].displayName;
}
}
Otherwise you can share your code.