Looking for logging into the Drupal 8 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 Drupal 8 site. After that you can login as usual with your login credentials.
https://www.drupal.org/forum/support/before-you-start/2017-04-29/how-to-login-to-drupal-admin-panel
https://www.drupal.org/project/securelogin
https://www.drupal.org/project/redirect_after_login
https://www.drupal.org/project/mail_login
https://www.siteground.com/kb/drupal_admin_login/
https://www.youtube.com/watch%3Fv%3DtpuXAwM1eZ0
https://www.youtube.com/watch%3Fv%3DgASKDC4ffgU
https://www.ostraining.com/blog/drupal/log-in-to-drupal-without-a-log-in-block/
https://drupal.stackexchange.com/questions/250597/programmatically-user-login-not-working
https://drupal.stackexchange.com/questions/249607/how-to-get-one-time-login-for-all-the-users
https://www.zoocha.com/news/user-login-drupal-8-aws-rekognition
https://github.com/oomphinc/d8-google-login
http://www.google.co.id/url?url=http://www.inmotionhosting.com/support/edu/drupal-8/getting-started/admin-login