I want to use GTL with Journey Data and Contact Data to personalize an Email with information stored in Contact Builder and information coming from an API event triggered by an external system. I am trying to do basic personalization to display an attribute for both cases.
Data Relationships were configured only in Contact Builder for Contact Data and the appropriate Event was created also in Data Designer. These codes are added inside an Email without any AMPScript. I am wondering why my code isn't working.