When logged in to your Diablo Immortal account on your mobile device, follow these steps to link to your existing* Battle.net account:

  1. Find the default profile icon and named Guest in the top left corner of your screen
  2. Click the icon
  3. Under I have an account, select the Log in button on the right of the screen
  4. In the pop up window, enter your Battle.net account email and password
  5. If you have a Battle.net Authenticator, approve the login from the authenticator app

If the steps were completed successfully, the game should now show your BattleTag instead of Guest.

*If you do not yet have a Battle.net account and would like to link to save your Diablo Immortal progress, create your free account here.