Creating a G2 account using your business email requires you to submit that email and create a password before a verification email is sent to your inbox.
If you received the verification email but the link is expired, you may have already verified your account. Try going to your G2 profile to see if your account lets you log in. If it does, you’re all set; otherwise, keep reading!
Check the spam folder for an email from noreply@g2.com with a verification link. If it’s still not there, you can create an account using your LinkedIn login, since that does not require a verification email.