WP_FAIL2BAN_BLOCK_USERNAME_LOGIN

Force login with email address/prevent login with username.

Default setting: disabled

Added in version 4.3.0.

/**
 * Force login with email address/prevent login with username.
 */
define('WP_FAIL2BAN_BLOCK_USERNAME_LOGIN', true);

Important

You should define this in wp-config.php even if you are using the Premium version of WPf2b.