Attach the response you already saved rather than creating a second roster entry.
For: Guests creating or signing into an account
Before you start: requirements and access
The original browser with its guest cookie and the original shared link. Save an RSVP first.
Steps
Reopen the game in the browser where you responded. Confirm Relay recognizes your guest name and response.
Choose Keep this game in Relay or Sign in from the saved-response area.
Finish authentication and any required account setup. Open saved game returns you to the game; the existing guest response is attached to your account.