Request to set a payment method as the default for a customer.
| contextName required | string The name for the context that the payment method should be set as the default for. For example, "checkout" or "subscription". |
| paymentMethodId required | string <uuid> The unique identifier of the payment method. |
{- "paymentMethodId": "b6df8625-cd25-4123-b345-638aa7b5d011",
- "contextName": "string"
}