ipa files are for iOS only.
Instructions to create a pkg file:
1. Create a Mac Installer Distribution certificate using the certSigningRequest from the SignerKeys folder.
View attachment 130374
2. Open Keychain Access on your Mac, choose b4j2-db keychain and add the mac_installer.cer file.
It should then appear in the My Certificates section:
View attachment 130375
3. Right click on the installer certificate - Get Info - copy the Common Name (starts with 3rd Party).
4. Run productbuild command line tool to build the package:
productbuild --component appname.app /Applications appname.pkg --sign "3rd Party Mac ..." --keychain b4j2
I haven't tried uploading the package to the app store. Please post your results.