Looking for logging into the Magento Installation Admin 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 Magento Installation Admin site. After that you can login as usual with your login credentials.
https://docs.magento.com/m1/ce/user_guide/store-operations/admin-login.html
https://devdocs.magento.com/guides/v2.3/install-gde/install/cli/install-cli-subcommands-admin.html
https://magento.stackexchange.com/questions/252069/after-installing-magento-2-3-admin-login-page-cant-open-properly
https://www.kotori.de/wissen/magento-login-admin-backend-nicht-moglich.html
https://www.templatemonster.com/help/de/magento-cant-login-to-admin-panel.html
https://github.com/magento/magento2/issues/563
https://stackoverflow.com/questions/2176195/cant-log-in-to-magento-admin
https://www.youtube.com/watch%3Fv%3D31l4WtMflcA
https://www.youtube.com/watch%3Fv%3DAJegs8vAFQ8
https://magento2.atlassian.net/wiki/display/m1wiki/Cannot%2Blog%2Bin%2Bto%2Bthe%2BMagento%2B1.x%2BAdmin%2BPanel%2Bon%2BLocal%2BInstallation
https://www.splendid-internet.de/blog/how-to-magento-2-komplett-auf-deutsch-installieren/
https://www.mag-tutorials.de/tutorials/installation-und-datenbank/magento-installation/
https://webkul.com/blog/magento2-admin-login-as-vendor/