Ran into an error implementing a CheckoutSessionsController subclass that customer_id didn't exist. Looks like there was a change a while back that missed renaming the usage to the parameter here: https://github.com/swerner/nocheckout/blob/daa093b58c71fad9a5cc12ef7cfee5d9fa7b4211/app/controllers/nocheckout/stripe/checkout_sessions_controller.rb#L74

I could be creating the subclass wrong...but from the readme examples it looks like you do it this way as well?

Got a small PR incoming to fix it, if it was just missed. If not, no big deal to close either!