Similar issue to https://community.constantcontact.com/t5/Developer-Support-ask-questions/V3-API-Retrieve-the-Authorization-Code/m-p/341896    Surprised this is not a more common request.   ... View more

This question has been marked solved, but it's really not solved.    If you have a website where users create accounts (a store or membership type site), it seems like you can't just add them to your Constant Contact list during the account create - it has to be done in a completely separate admin flow so the Constant Contact accountholder can authenticate and permit adding to the list.    ... View more