Workfront API - LinkExternalObject action on Project

Dear All,

We have configured a custom integration for documents.

Each time a project is set-up we create the document placeholders in our DAM.

Once this done I'd lke to automatically link our Dam Folders to the coresponding project.

There's this action at the project level: LinkExternalObject as described here:

https://developer.workfront.com/projects.html#put-/proj/linkExternalObject 

Does anyone have managed to make it work? If yes could you please share what exact parameters we need to give...?

Any help will be greatly appreciated!

Best