Unable to add academic email

I signed up for an account previously with my personal email address, and now my free trial period ended so I would like to change my account to an academic account. When I was applying for a switch to academic account, I was unable to add new email address (I wanted to add my school email).

When I clicked add email in my profile, I was redirected to a sign up website with options like github, google, microsoft or custom email domain. I keyed in my school email address in the custom email domain but I kept getting error: “We’re sorry, something went wrong when attempting to sign up.”