assets section of the
pubspec.yaml file, otherwise they cannot be found.
Read the official Flutter documentation Adding assets and images for more details.
Example of a
... # The following section is specific to Flutter. flutter: # The following line ensures that the Material Icons font is # included with your application, so that you can use the icons in # the material Icons class. uses-material-design: true assets: - assets/index.html - assets/css/ - assets/images/ ...