Stripe setup is handled in [`config/initializers/stripe.rb`](https://github.com/codidact/qpixel/blob/a3198da169c6ecdcce38202fb1f60a07cbcb0389/config/initializers/stripe.rb), where the Stripe API key is set based on the values saved in the Rails credentials file.
You _should_ be able to run `rails credentials:edit` (set the EDITOR environment variable to whatever command line editor you use first), and set `stripe_test_public` and `stripe_test_secret` to any non-empty string, and that should work as long as you're not actually running any Stripe related operations.