I want to know if I can use the stripe express checkout element for subscription?

I use ruby btw

Based on the document, one of the modes made it seem possible:

const elements = stripe.elements({
  mode: 'payment', // This can be `subscription`
  amount: 1099,
  currency: 'usd',
  appearance,
})

I have a lookup key for the subscription price. I was hoping to use it somewhere once the payment method is confirmed here:

const handleError = (error) => {
  const messageContainer = document.querySelector('#error-message');
  messageContainer.textContent = error.message;
}

expressCheckoutElement.on('confirm', async (event) => {
  const {error: submitError} = await elements.submit();
  if (submitError) {
    handleError(submitError);
    return;
  }

  // Create the PaymentIntent and obtain clientSecret
  const res = await fetch('/create-intent', {
    method: 'POST',
  });
  const {client_secret: clientSecret} = await res.json();

  const {error} = await stripe.confirmPayment({
    // `elements` instance used to create the Express Checkout Element
    elements,
    // `clientSecret` from the created PaymentIntent
    clientSecret,
    confirmParams: {
      return_url: 'https://example.com/order/123/complete',
    },
  });

  if (error) {
    // This point is only reached if there's an immediate error when
    // confirming the payment. Show the error to your customer (for example, payment details incomplete)
    handleError(error);
  } else {
    // The payment UI automatically closes with a success animation.
    // Your customer is redirected to your `return_url`.
  }
});

I want to create the subscription at the return_url. But based on the provided document, it’s only for a one-time payment.

So if I did this (without using the subscription price id and just create the subscription of the customer at the return url). They will gonna be two charges, one for the one-time payment at express checkout and the second on when the subscription is created.

Any help?