To use Stripe with Pay, you'll need to add your API keys and Signing Secret(s) to your Rails app. See Configuring Pay for instructions on adding credentials or ENV Vars.
You can find your Stripe private (secret) and pubilc (publishable) keys in the Stripe Dashboard.
Webhooks use signing secrets to verify the webhook was sent by Stripe. You can find these on your Stripe Dashboard or the Stripe CLI.
The Webhooks page on Stripe contains all the defined endpoints and their signing secrets.
View the webhook signing secret used by the Stripe CLI by running:
stripe listen --print-secretSee JavaScript