I wanted to switch from Stripe v3 to Stripe v3 in order to use the promo codes feature, but I don’t see any option to do that in the plugin page. The only option I have when I interact with it is Stripe v2. Halp!
Hello Tal.
Have you tried reinstalling the plugin? 
Currently, Bubbe’s Stripe plugin works correctly.
Also maybe try upgrading Bubble version to the most recent one, under Settings → Versions
Hope this helps.