Enable Users to Log In with Their Email, Phone Number, or Any Identifier You Choose
Where: This feature is available in all communities, accessed through Lightning Experience, Salesforce Classic, and all versions of the mobile app. This feature is available in Enterprise, Essentials, Performance, Unlimited, and Developer editions.
How: Build Login Discovery login pages on the Login & Registration page of the Administration Workspace. Choose the Login Discovery Page login type, which generates a login handler that you extend in Apex. You can locate the login handler from the Setup Apex Classes page. Its name begins with AutocreatedDiscLoginHandler.