There may be occasions when you would like to change the login method that you chose when originally setting up your OpenSimSim account. Two login methods are supported;
Login with your mobile number and a password that you set
Login via your Facebook account credentials.
This article describes the process of switching from Password (#1) to Facebook (#2). A similar process applies in reverse, should you wish to switch from Facebook to Password.
Login to the Mobile App and go to More Menu > Account Settings > Account Security > Login Method
Tap on 'Login Method' to display the following screen. Select 'Facebook'
You are now prompted to login to your Facebook account. Doing so, allows Facebook to pass your login credentials to OpenSimSim, which are used for verification when you subsequently log in to your OpenSimSim account.
At any time, you can revert your Facebook login method to use your mobile number & password. When logged in to your OpenSimSim account, simply go to More Menu > Account Settings > Account Security > Login Method, choose 'Password' and follow the prompts to complete the process.