Looking for logging into the Sharepoint Change Password First site and are not getting the correct working link for it? In such a case, you can use the links given here by searching your desired login page in the search box. If the page is present on our website then you will get all the links related to the Sharepoint Change Password First site. After that you can login as usual with your login credentials.
https://sharepoint.stackexchange.com/questions/120067/how-to-force-change-password-on-first-login-for-fba-user
https://social.technet.microsoft.com/Forums/en-US/fe712c98-d76b-462d-8a09-2a96e937a40e/require-user-to-change-password-at-next-login?forum=sharepointadminprevious
https://docs.microsoft.com/en-us/sharepoint/administration/configure-automatic-password-change
https://www.harepoint.com/Products/HarePointPasswordChange/Default.aspx
http://www.boostsolutions.com/password-change-expiration-tutorial.html
https://serverfault.com/questions/218298/is-there-a-way-to-allow-administrators-to-change-or-reset-user-passwords
https://www.c5insight.com/Resources/Blog/tabid/148/entryid/337/Tips-to-Avoid-Login-Prompts-in-SharePoint.aspx
https://www.c5insight.com/Resources/Blog/tabid/148/entryid/275/sharepoint-login-issues-how-to-fix-users-who-cant-log-in-via-their-user-principle-name-upn.aspx
https://threewill.com/reset-a-sharepoint-2013-service-account-password/
https://www.virtosoftware.com/sharepoint/password-reset-web-part
https://www.eliostruyf.com/change-the-active-directory-user-password-through-sharepoint/
https://bamboosolutions.com/sharepoint-web-parts/password-change/
https://www.manageengine.com/products/self-service-password/active-directory-change-password.html