Give users the ability to import

Enabling document sharing

Give users the ability to import and export documents from your app.

https://developer.apple.com/documentation/uikit/view_controllers/adding_a_document_browser_to_your_app/enabling_document_sharing

Setting up a document browser app

Add a document browser view controller to your app.

https://developer.apple.com/documentation/uikit/view_controllers/adding_a_document_browser_to_your_app/setting_up_a_document_browser_app