The URL is a file URL pointing to a location inside my Group Container: /Users/username/Library/Group Containers/group.com.username.appname/Temp I am using the Group Container because my share sheet is called from inside an AUv3 Extension sandbox. Would that make a difference compared to a 'regular' standalone app?

This is good news, as I have a legacy app already in the iOS Appstore for a few years so I can't migrate to a different group naming scheme. Does this mean that when I now bring my catalyst app to the Mac Appstore that my users won't get the annoying popup? If it's only a nuisance for me during development that's a pain I can live with.