QIOSFileDialog: Could not resolve Qt plugin that gives access to photos on iOS 

import QtQuick
import QtQuick.Controls
import QtQuick.Dialogs
import QtCore

Window {
	id: root

	FileDialog {
		id: fileDialog
		title: qsTr("Choose a folder with some images")
		//options: FileDialog.DontUseNativeDialog	// | FileDialog.ReadOnly
		options: FileDialog.ReadOnly
		fileMode: FileDialog.OpenFile
		modality: Qt.WindowModal
		currentFolder: if (Qt.platform.os === "ios") { return "file:assets-library://"; }			// same issue, initialy tried StandardPath for iOS with same result
				else { return StandardPaths.standardLocations(StandardPaths.PicturesLocation).pop(); }
		
	}

	Component.onCompleted: fileDialog.open()
}

    <key>NSPhotoLibraryUsageDescription</key>
    <string>This app requires access to your pictures</string>