The image_picker package needs two additional packages, image_picker_android and image_picker_platform_interface. Then you can continue using ImagePicker().pickMultiMedia() on both Android and iOS.

setup the main.dart file:

void main() {
 final ImagePickerPlatform implementation = ImagePickerPlatform.instance;
 if (implementation is ImagePickerAndroid) {
  implementation.useAndroidPhotoPicker = true;
 }
 
 ...
}