I need help how to Embed Registration ID into Marketing email for Check-In, as am developing a mobile that will scan this registration id and log a check-in record on MS Dynamics 365 Marketing, the problem am facing that i can't embed the registration id into the Marketing email and i have done these steps and reached a dead end:
1- Sync Event Registrations with Customer Insights.
2- Try to use assist edit to fetch this field but couldn't.