Service Devtest 504

I am trying to open service.devtest.ringcentral.com but it keeps giving me 504 Gateway error

I was trying to open portal from console of https://developers.ringcentral.com, but it redirects me to this url and gives 504 gateway

https://service.devtest.ringcentral.com/login/main.asp?CDEB1210:D2052A001CDC9401EF7EE4678F210D67AD8ED6&enc=2&rdr=/adminHome.html?postLogin=true

I have tried different account, incognito mode, different browser and resetting password, but it does not get passed login