Since Ozone 9 has been succeeded by Ozone 11, finding the older version for free usually happens through specific "Legacy" giveaways.
A powerful dynamic EQ that handles the "corrective" part of mastering perfectly.
Use the Music Production Suite trial on Splice or iZotope’s own site to use the full version for 14–30 days.
If you can't find a legitimate free copy of Ozone 9, Reddit’s production community highly recommends these 100% free mastering plugins:
While not free, Splice offers Ozone for about $10/month, allowing you to stop and start whenever your budget allows. Top Free Reddit-Approved Alternatives