Could not find action, lane or variable 'appicon'

[Jukez17]

It seems that the appicon action is not working on the iOS.

I have following lane:

  lane :icon do
    appicon(
      appicon_image_file: 'fastlane/metadata/logo-1024.png',
      appicon_devices: %i[ipad iphone ios_marketing watch watch_marketing],
      appicon_path: 'Images'
    )
  end

that results to Could not find action, lane or variable 'appicon'. Check out the documentation for more details: https://docs.fastlane.tools/actions when running bundle exec fastlane icon

[warpling]

If you do what it says you'd find you answer in the very first sentence of the Getting Started Guide.