If you created your account with an email:
- Go to your Profile (the fifth icon in the navigation bar on the main screen).
- Select Edit Profile.
- Tap the Link to Facebook option.
To unlink a profile from the social network app, follow the same steps and select the Unlink button.
It is important that you link your Facebook profile after logging in with your email and password. If you choose Sign in with Facebook without signing in, a new account will be created with that information.