The registration may not have been completed in CanvasWorkspace.

Check if the registration confirmation email message from CanvasWorkspace arrived.

If it has arrived, access the URL in the email message, and then complete the registration.

If the email message has not arrived, check if it arrived in your junk mail folder or if spam filters have been set.

For details, refer to "I registered with Artspira, but the email/PIN (for account) did not arrive".