Yes, correct, via the 'Add the Platforms...' button and then the "Supported Destinations":

Thank you so much, really appreciate it. The fix was as follows: download iOS 26.1 and then added to supported destinations iPhone and iPad. It works now.

Here are the #Preview macros (commented out for now because they don't seem to to anything at this point)

Here are the platforms:

Thank you for replying! This is the image I have; notice that the selection 'Automatic - iPhone 17 Pro' is missing.