Unfortunately, this will not work for many of us. My problem did not arise until i purchased a new phone (13 Promax). Since the app cannot be loaded onto the new phone, there is no data to backup to the laptop. Apple erased my old phone as a part of the purchase of the new phone, so unless the developer will provide the latest of whatever was in its server at the time that Apple discontinued allowing the app, then we cannot retrieve the data.
Again, Apple should have warned of this when it discontinued carrying the app; and again when Apple sold the new phone to me.
Apple sold the app to me, Apple collected the annual fees associated with the app, Apple sold the new phone to me, so Apple has the responsibly to get with the developer and do whatever it needs to do so that its customers can retrieve their important docs, photos, and videos.
Apple, what are you going to do?