I thought Destiny 2 was free to play but there is no option to get the game on the Stadia store without buying one of the bundles. Where can I get the free version if the game?
Destiny 2 should be free to play for Pro subscribers. And since that should pretty much be everyone right now, you should be able to claim it... unless your 2-month pro has not been activated yet (from the blog post, wait until tomorrow).
If by Saturday you still don't see Destiny 2 available, you should reach out to Stadia Support.
The game itself is free on all other platforms. That should mean anyone should be able to "purchase" it and play, regardless of subscription. Why is a free game locked behind a paywall? Are all free-to-play games be limited to Pro subscribers only?