Run in terminal :

flutter pub run simple_assets_generator:generate -i assets/path/files -o lib -n Images -ext jpeg,png -fn asset_names

required -i assets directory, in my case assets/path/files

required -o generated file output path, lib/assets_names in my case

optional -n generated class name

optional -fn generated file name

optional -ext generate only if file extension in given extensions

Open pub.dev

class TxtFiles {
  static String fileTxt = 'assets/path/files/file.txt';
}

class Images {
  static String fileTxt = 'assets/path/files/logo.png';
}