We have a macOS app, SheetPlanner, that supports sharing a document with other people for collaboration, via iCloud Drive. When someone shares a document in Apple Pages, e.g. via email, and someone else clicks the link to open the document, the panel offers to open the document "in Pages", and opens the document directly in the app:
But when we do the same with a SheetPlanner document, it is missing the "in SheetPlanner" part, and instead displays the document in the Finder:
What are we missing? How can we get the iCloud sharing mechanism to offer to open in the app?
Here's a video that demonstrates this:
https://dropbox.com/s/bh9ipmn3h9ucpfc/Pages%20V%20SheetPlanner%20Sharing%20Behaviour.mov?dl=0