There is a tutorial on Chris Ching’s YouTube channel. Link here: Figma Tutorial for Mobile Design (2020) - YouTube
I found there nothing about what did I ask you. Can you tell me which videos there explain how to export from Figma the app icons with 2x and 3x formats such that these content would be applicable for the app icons and for app store iOS cell in Xcode?
Why don’t you try searching YouTube for something like “how to export iOS asset images from Figma”.
One of the most important skills you can have is how to search for stuff online.