TABLE OF CONTENTS
Issue
Mac gives an error about stages sync application being from "unidentified developer"
Explanation
Mac requires developers to be "known" to install applications without a warning for security reasons. Today's Plan is not certified for this authentication however the application can still be installed following the steps below.
Troubleshooting
See this support article to install applications like Sync: https://support.apple.com/guide/mac-help/open-a-mac-app-from-an-unidentified-developer-mh40616/mac