Backup/Archive a particular version of an app

How can I archive a my currently installed app version (particular version) of an iOS app (=export IPA file?) I am aware that apple removed the App Store from iTunes and that apps are not part of the backups any more. However I am looking for a solution with which I can draw my currently installed app version as IPA file before I upgrade. Since app authors can modify and remove functionality at will and Apple prevents people from going back to a previous version I would like to be safe, particularly when large changes happen. I have looked into iMazing but it only seems to be able to export the latest version from the AppStore to IPA (neither the currently installed version nor different version)