Oracle cloud: Login

Main problem for login into Oracle cloud is to there is no generic login URL.
Inside the mail Oracle sent after the registration there is a specific URL. Something like:

http://app.response.oracle-mail.com/e/er?elq_mid=920.......

But this ends after some seconds at:

https://cloud.oracle.com/en_US/sign-in

 

There is also another login page, but this one does not work for my setup:

https://login.eu-frankfurt-1.oraclecloud.com/v1/oauth2/authorize

For this one i did not find any documentation at all, so i somebody knows how this login page can be used, please add a comment...