As of now, the email addresses can't be updated manually in the app or via dashboard if the guest's account is connected to Facebook.
However, if "Facebook Webhook" is enabled for the business, then the guest can update the email address in the app.
- Update/Modify the email address for the Facebook account.
- Once facebook account's email is updated, guests have to try logging in (Connect via Facebook) with the app again.
- This will sync and update the email address in the app and the guest's email will be updated successfully.