I cannot create password for the first sign in

I registered a student plan with my academic email, when I click the button Bekræft din konto and enter the password, there's always this error happening, even when I didn't finish filling out my password. When I try to log in again, with the authentification number sent to my email, it kept happening so now my account's temporarily blocked. It's fine for my Google account. Now I need to log in to my institution account to cancel the plan, kind of disappointing! Any helps? Thank you.