Save button not working..

Hi,

I tried to install the plugin. I could get the access code through google access verification. I pasted the code and pressed the save button and it just rotates. Nothing happened. I read from other tickets to change two values from true to false. I did, and nothing changed.
I contacted with my host technical support and they said cURL is activated in their host.
I tried with incognito browser, different google account nothing worked. And finally, I revoked the previous access code and tried again, it didn’t work with new access code neither.
Any idea how to solve the issue?

The page I need help with: [log in to see the link]