The Fitbit SDK Toolchain is used to build Fitbit OS apps and clock faces.
Install Fitbit SDK Toolchain to your project and run npx fitbit-build to compile your app!
The toolchain can be used to generate a new appID for your project. This is useful when you copy an existing project and want to publish it as a different app on the App Gallery.
npx fitbit-build generate-appid
For help regarding the tools please consult the Fitbit Developer Portal or Fitbit SDK Forums