Looking for logging into the Magento Frontend 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 Frontend site. After that you can login as usual with your login credentials.
https://magento.stackexchange.com/questions/181123/how-to-login-saperately-from-magento-frontend-using-admin-credential
https://community.magento.com/t5/Magento-1-x-Technical-Issues/1-9-2-users-can-not-log-into-front-end/td-p/11958
https://www.sitepoint.com/fix-magento-login-issues-cookies-sessions/
https://stackoverflow.com/questions/12510693/magento-login-to-frontend-with-admin-credentials
https://inchoo.net/magento/administration-magento/login-as-customer-magento-extension/
https://www.youtube.com/watch?v=qaVYst_ok34
https://www.templatemonster.com/help/magento-how-to-fix-customer-login-issue.html
https://www.magentech.com/forum/368-sm-paradise-responsive-magento-theme/12491-customers-cannot-login-on-frontend
https://learncodeonline.in/lets-fix-magento-login-issues-using-cookies-sessions/
https://www.mageplaza.com/kb/how-to-enable-customer-login-register-captcha-magento-2.html
https://amasty.com/knowledge-base/
https://stuntcoders.com/magento-tutorials/magento-customers/registering-customer-front-end/
https://github.com/amzn/amazon-payments-magento-2-plugin/issues/420