Once you are in the location subaccount:
1. Check what SMTP they are using, if Omnix support is connected in the SMTP integration, the user needs to log in as Omnix support and send the review request.
2. Check if the Email content has any Custom Values and check if they look good.
3. If they use Mailgun, there might be a delay.
Article mentioned
Limitation of using SMTP when emails are not sending:
Reviews, Review Requests, and the Omnix Review Widget: