I would like to know if it's possible to create a custom data entry that pulls in data via an external database hosted in heroku. Will it be opening an API on my side? or would i be posting on a scheduled basis to a specific API in SFMC?
As of now, majority of the answers has been to pull in data via existing data extensions. And if so, am i able to replicate the functionality of how Salesforce Data Entries work?
My current connection is SFDC <-> Marketing Cloud Connect <-> SFMC