It looks like security scoped bookmarks are a macOS-only feature. I'm running into this issue on iOS. Is there an API that I'm not seeing? I created a ticket in Feedback Assistant (FB16091226)

That makes sense, but how to I gain permissions to access the file? It's an attachment to the INSendMessageIntent that my app is handling, so there should be some way for my app to gain access to it, right?

Did you make any progress with this? I'm having the same trouble. I'm unable to open the file URL with ExtAudioFileOpenURL(), and startAccessingSecurityScopedResource() returns false.

I was able to mostly disable the feature by only setting isSecureTextEntry in the text field delegate's textField(_:, shouldChangeCharactersInRange:, replacementString:). Sometimes it would still try to offer an automatic password. Please log a bug? There are a lot of parts of password autofill that feel incomplete.