Unable to purchase credits: Stripe checkout fails before payment page opens

What issue are you seeing?

I am unable to purchase credits because the checkout/payment page does not open.

When I try to proceed to payment, the app returns the following Stripe-related error:

{
  "detail": "Error communicating with Stripe: {
    \"error\": {
      \"message\": \"`To allow a payment method to be redisplayed, the payment method must be saved to the Customer. Use `payment_intent_data.setup_future_usage` or use setup or subscription mode to save the payment method to a Customer.`\",
      \"request_log_url\": \"[REDACTED_STRIPE_REQUEST_LOG_URL]\",
      \"type\": \"invalid_request_error\"
    }
  }"
}

It looks like the Stripe Checkout/PaymentIntent configuration may be trying to redisplay a payment method that has not been saved to a Customer.

What steps can reproduce the bug?

1. Open Codex Web Panel.
2. Go to the credits / billing / purchase credits flow.
3. Select an option to buy credits.
4. Click the button to continue to payment.
5. Instead of being redirected to the Stripe payment page, the request fails with the Stripe error shown above.

I cannot complete the purchase because the checkout page never opens.

What is the expected behavior?

I expected to be redirected to the Stripe checkout/payment page and be able to complete the credit purchase.

The payment flow should either:

• create a valid checkout/payment session, or
• save the payment method to the Customer when redisplay is required, for example via payment_intent_data.setup_future_usage, setup mode, or subscription mode.

Additional information

This appears to be a billing/payment integration issue rather than a local environment issue.

The error comes from Stripe and says:

To allow a payment method to be redisplayed, the payment method must be saved to the Customer.

I have redacted the Stripe request log URL because it may contain account/request-specific information.