How to load a LaunchDaemon inside a bundle in postinstall?

We have a launch daemon installed to /Library/LaunchDaemons which is loaded in the installer's postinstall by "launchctl load /Library/LaunchDaemons/com.company.AppName.service.plist". Since there have bin problems with the service starting on startup on ventura, we tried to install the plist-file into the bundle to /Contents/Library/LaunchDaemons, as recommended in the article "Updating helper executables from earlier versions of macOS", for installations on ventura. The problem is, that loading it in postinstall by "lauchctl load /Applications/AppName.app/Contents/Library/LaunchDaemons/com.company.AppName.service.plist" fails with "Load failed: 125: Domain does not support specified action". launchctl seems not to be prepared to handle LaunchDaemons included in bundles. So how can I load my launch daemon in postinstall?