In which course, I can learn about UIImagePickerController ?
Are you following a UIKit course or SwiftUI?
If you are coding in SwiftUI then there is now a PhotoPicker API available in SwiftUI (as of iOS 16) which means you do not have to resort to creating a UIViewRepresentable object to deal with the PhotoLibrary.
Chris Ching has not covered this as yet so take a look at this from Paul Hudson: