On a test machine:
1. Install the Jamf Pro Tools
2. Run this command in terminal mkdir -p /tmp/folderlocation
2. Drag the file.pkg and config.json files to /tmp/folderlocation
3. Open composer, and drag the folderlocation folder you created into the left side of Composer
4. Add a postinstall script in Composer with the following command: installer -pkg /tmp/folderlocation/SecureAuth.pkg -target /
https://community.jamf.com/t5/jamf-pro/copying-files-locally-off-server-for-install/m-p/159145