Iframe with allowpaymentrequest property does not allow express payment methods

Summary

stripe.paymentRequest does not have the same result as the native PaymentRequest when calling canMakePayment within an Iframe. The Iframe has the allowpaymentrequest attribute as specified in the documentation.

Other information

Sample stripe code

const paymentRequest = stripe.paymentRequest({
      country: 'US',
      currency: 'usd',
      total: {
        label: 'Demo total',
        amount: 0,
      },
      requestPayerName: true,
      requestPayerEmail: true,
      requestPayerPhone: true,
      requestShipping: true,
      shippingOptions: [],
    });

    paymentRequest.canMakePayment().then(result => {
      if (result) {
        // Always null
      }
    });

Sample native PaymentRequest code

new window.PaymentRequest(
      [
        {
          supportedMethods: 'https://google.com/pay',
          data: {
            ...
          }
        },
      ],
      {
        total: {
          label: 'Total',
          amount: {
            currency: 'USD',
            value: '0.00',
          },
        },
      },
    )
      .canMakePayment()
      .then(canPay => {
        // Returns true
      });

[hofman-stripe]

There hasn’t been any changes that would cause Google Pay to stop working if it was before, neither in Chrome nor in Stripe.js. The main reason Google Pay wouldn’t work is if the Google Pay Payment Handler is not installed (Google Pay never used before on the browser), or if no cards are saved in the Google Pay wallet. You can verify the former by checking if a service worker with scope https://pay.google.com/gp/p/ is installed in chrome://serviceworker-internals/

[wesleyyee]

@hofman-stripe So has anything changed recently? The google pay functionality used to work but no longer does