Looking for logging into the Gae 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 Gae site. After that you can login as usual with your login credentials.
https://appengine.google.com/
https://gae.org/login/
https://cloud.google.com/appengine/docs/standard/python/users/loginurls
https://stackoverflow.com/questions/48701354/go-client-to-access-gae-login-required-apps
https://github.com/smartninja/gae-login-boilerplate
http://pv.gae2.org/vt_introra19.asp
https://www.youtube.com/watch?v=XQKnl-HW9sw
https://gae-valutazioni.bnppre.com/
http://correo.upr.edu/
http://camel.apache.org/maven/current/camel-gae/apidocs/org/apache/camel/component/gae/login/package-summary.html
https://vt4help.service-now.com/sp/View,%20Change,%20or%20Reset%20Network%20Password?id=kb_article&sys_id=92c66438db7f07001c1e86171b961978
https://packagist.org/packages/gonzalo123/silex-gae-login-provider
http://www.gwtproject.org/doc/latest/tutorial/appengine.html