I can't start my trial because the account activation email is not working

I did not receive the activation email or the link displays an error

I did not receive the activation email and it is not in my blocked folder or

I received the activation email but when I followed the verification link, the system displayed the error No user found (invalid activation link).

To resend a new verification email:

Select your subdomain from the menu below or recall the subdomain you chose when signing up

Type the email you used to sign up for the account and press Submit.
Choose subdomain

See:

How long are account verification emails and password reset emails valid?

How do I reset my password when I can't sign in?

Note: The options to verify email addresses are not available until you activate your help center. For more information, see Getting started with your help center.