Looking for logging into the Burp 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 Burp site. After that you can login as usual with your login credentials.
https://portswigger.net/users
https://support.portswigger.net/customer/login
https://support.portswigger.net/customer/portal/articles/1964020-using-burp-to-brute-force-a-login-page
https://support.portswigger.net/customer/portal/questions/17187198-authenticated-scanning
https://portswigger.net/burp
https://support.portswigger.net/customer/portal/articles/1964073-using-burp-to-hack-cookies-and-manipulate-sessions
https://support.portswigger.net/customer/portal/articles/1855752-managing-your-burp-account
https://support.portswigger.net/customer/portal/articles/2363088-configuring-burp-s-session-handling-rules
https://www.burps.com.au/portal/index.php
https://www.alpinesecurity.com/blog/brute-forcing-login-page-with-burp-suite
https://www.n00py.io/2017/10/how-to-burp-good/
https://www.redsiege.com/blog/2018/09/maintaining-session-states-in-net-apps-with-burp/
https://www.gracefulsecurity.com/burp-macros-re-authentication/