If you are looking for specific version info for , it is primarily found in official release notes and manuals.
A well-known advertisement offered Iris 2 (valued at $149) for free with any purchase or via a specific coupon code during limited-time promotions. advertisement iZotope Iris 2 v2.02c for Mac Free Download
Version 2.02c was an update specifically for macOS 10.15 (Catalina) support. If you are looking for specific version info
Note that there is a separate academic tool called IRIS 2+ used in solar physics research to recover radiative losses in the solar atmosphere. This is unrelated to the iZotope music software. Product Documentation and Version Details advertisement iZotope Iris 2 v2.02c for Mac Free Download
The "Free Download" advertisements often referred to legitimate promotional giveaways: