Looking for logging into the Gmail Double 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 Gmail Double site. After that you can login as usual with your login credentials.
https://productforums.google.com/forum/#!msg/gmail/0y2B2QNd1Ts/4M18E-yNCwAJ
https://www.google.com/landing/2step/
https://webapps.stackexchange.com/questions/119946/why-do-i-need-to-login-to-gmail-twice
https://support.postbox-inc.com/hc/en-us/articles/202197850-Multiple-or-Repeated-Login-Screens-or-Password-Prompts
https://www.reddit.com/r/GMail/comments/9jsz6w/anyone_know_why_i_keep_having_to_login_twice/
https://blog.techinline.com/2017/10/18/how-to-fix-double-login-issue-on-windows-10-fall-creators-update/
https://support.google.com/accounts/answer/1721977?co=GENIE.Platform%3DDesktop&hl=en
https://support.google.com/accounts/answer/185833?hl=en
https://www.laptopmag.com/articles/set-up-gmail-2-factor-for-outlook
https://help.roboform.com/hc/en-us/articles/115000416712-Why-isn-t-automatic-log-in-working-in-Gmail-
https://www.lifewire.com/secure-your-gmail-account-with-password-and-phone-authentication-1171958
https://www.turnon2fa.com/tutorials/how-to-turn-on-2fa-for-gmail-2/
https://www.independent.co.uk/life-style/gadgets-and-tech/news/gmail-two-step-verification-2fa-google-account-users-security-feature-cyber-crime-a8172391.html