By default, authentication with email addresses and passwords is disabled. If possible, we recommend setting up authentication with your installation of GitHub (Enterprise), Bitbucket.org, Bitbucket Data Center / Server, or GitLab using OAuth instead.
Navigate to the "Global Configuration" section from the admin page to get to the form below. Enable login and account registration with email addresses and passwords by selecting the option in the form and submitting the form via the "Update configuration" button.