I have gone through this reference app that has provided in documentation https://github.com/zoom/zoomapps-advancedsample-react.
I am confused because there is no trace of @zoom1234/appsdk in any package.json file and never imported zoomSdk in any file or component and yet the app is able to perform zoomSdk operations.
All I see is a comment - /* globals zoomSdk */ in every file.