Can't add app from SharePoint Store - "Attribute Prerequisite ID is missing."

I'm trying to add an app from the SharePoint Store to my on-prem App Catalog site.

The app I want to add is grayed out and says

"You can't add this app here",

and when I click on it I get the error

"Attribute Prerequisite ID is missing."

I've tried googling around to find out what this means exactly and how to fix it, but I can't seem to find anything.

Anyone know what this means? (And how to fix it?)