This is a launchDaemon that works with Setup Manager for Jamf Pro and Jamf School.
See this blog post for background.
Download the repo and adapt the setupManagerFinished.sh script to your needs. The code you want to adapt is in lines 39 through 47.
The default script triggers a custom policy trigger (setup_manager_finished, defined in line 10)
The buildSetupManagerFinishedPkg.sh script will assemble the LaunchDaemon plist, the script and the installation scripts into a pkg.
You will have to adapt the name of the certificate you use to sign the pkg in line 20. If you do not have a signing certificate, you can set signature="" and the script will build an un-signed pkg. You need a signed installer pkg when you want to add it to the Jamf Pro Prestage or install it with Jamf School. But if the pkg is not signed, you can still install it with a Jamf Pro policy with a Setup Manager action. As long as it is installed before Setup Manager finishes, it will trigger when the flag file gets created.
Code is provided as-is. You can join us on the Mac Admins Slack in the #jamf-setup-manager channel for discussions.