Correct, but how do you add an asset in aem automatically to workfront? the user should add it manually in the projects's document area, right?
and in this case the client has hundreds of assets in an external repository, we need to migrate them to the aem-workfront ecosystem so I think the right thing to do would be to import them into workfront in their respective projects so that automatically thanks to the connector the folders are created in aem and the assets are sent
I haven't come across a way to automatically send an asset from AEM to Workfront and create a link between the two. Only the manual route you mention. In the use cases I've come across, assets are typically added to Workfront as and when they need to be worked on / updated and then sent back to AEM. Not the other way around.
If you find that adding to Workfront first is the right way to go, you'll likely need to build something to programmatically upload the assets and their metadata to the linked folders you have created in Workfront using the Workfront API.