☒ I am really trying to help guide you without giving all of the answers because there is so much in learning to troubleshoot these issues. In your particular case, the Stripe::Source.create has a required parameter called type. Since it would be impossible (or improbable) for anyone to know what that means except for the Stripe developers, it's important to look at their provided documentation. In this case, the Stripe::Source.create points to this reference in the documentation. https://stripe.com/docs/api/sources/create#create_source-type Since they don't give much meaning to what the type parameter is as far as the available values, we need to look at the source object. https://stripe.com/docs/api/sources/object#source_object-type Since you're taking in credit cards, you would use the type "card"