We have the following challenge:
The question is how our users in Portal are going to get access to an application shared by the municipality to our ArcGIS Online collaboration? Is there a way to register an application in Portal with user credentials?
Hope somebody has some suggestions!
Have you looked into AEC Project Delivery? It might be a viable option depending on whether it is your org. or the municipality that implements it.
https://www.esri.com/arcgis-blog/products/arcgis-online/aec/introduction-to-aec-project-delivery/
We have not, thank you for making me aware of this option! However, I would love to see a more out of the box approach from Esri, instead of having to buy another product.
Ideally, we would like to see the possibility to add an application to Portal and save the credentials, as we do now with REST services registered on the platforms.