Explanation
To make sure that all of the Salesforce users log in using the branded login URL after deploying my domain, and give them a grace period for updating their bookmarks, the administrator should set the Redirect policy to Redirect with a warning to the same page within the domain. This will redirect users who try to log in from
https://login.salesforce.com or another domain to https://nto.my.salesforce.com, and show them a warning message that they need to update their bookmarks. Setting the Login policy or preventing login from
https://login.salesforce.com will not redirect users or give them a warning. Filtering with Form Factor will not affect login URL. References:
https://help.salesforce.com/s/articleView?id=sf.domain_mgmt_redirect.htm&type=5