Problem entering my lessons

I press get started and nothing happends although in the morning it was running properly.What should I do?

if you scroll down a bit do you see the list of certificates?

I see the loading placeholder in the nav bar there, which usually indicates an issue connecting to the API server.

Can you see any errors in your browser console? And can you confirm that you’re on an internet connection of sufficient speed?

Oh that’s it
I used opera and everything is working properly.
But why chrome is the problem?
Everything else is okay when using chrome.