You should have gotten an email from Scale Studio, asking you to join your administrator's team. Click the activation link and create a password.
If your token isn't working, contact your administrator and ask them to re-invite you to the platform. If you didn't open the invite link within 24 hours, your sign up token will be invalidated.
Follow the link and you'll be taken to create a Studio account
If you already have an account with Scale, you can navigate to the log-in page instead