I’m being told I have to reset my iPhone back to factory settings
That image says if you're having problems you can reset it, not that you have to reset it.
The image doesn't show the entire window, so you don't show us whether the other tabs are available, such as the Files tab which is where you would be able to drag & drop a file to add it to an app.
Topic:
Community
SubTopic:
Apple Developers
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