I don't see your data or schemas so will just outline some generic steps to try: 1. Make sure that your two XDM Profile based schemas have exactly one primary identity marked, and if those two identities aren't in the same namespace, then at least one of those schemas must have a secondary identity ...

If you are here: https://platform.adobe.com/home and you don't see the word "Destinations" on the left hand side of the page immediately underneath the word "Sources" then your instance of AEP (or your current AEP sandbox) has not been provisioned with Real-time CDP: https://docs.adobe.com/content/h...

You can always start on the home page: https://platform.adobe.com/home And click on the word "Identities" on the left hand side of the page. -Kevin

Can't know for sure, but possibly you've put your identity information in the identityMap field and it doesn't match the namespaces in your AEP instance?  Recommendation is to not use the identityMap field - ever - but instead label a string field as a primary identity in your schema. The field must...