Send parameters via fetch to Python view for Stripe checkout

I have a Stripe endpoint set up in Python, looks like this:

def create_checkout_session(request):

donation_amount = request.POST['donationAmount']
donation_name = request.POST['donationName']

try:
    checkout_session = stripe.checkout.Session.create(
        line_items=[
            {
                'price_data': {
                    'unit_amount': donation_amount,
                    'currency': 'usd',
                    'product_data': {
                    'name': donation_name
                    },
                 },
                 'quantity': 1,
            },
        ],
        mode='payment',
        success_url=settings.DONATION_URL + '?success=true',
        cancel_url=settings.DONATION_URL + '?canceled=true',
    )
except Exception as e:
    return str(e)

return redirect(checkout_session.url, code=303)

And I'm trying to send the donationAmount and donationName via a fetch function.

const goToCheckout = (donation, userHandle) => {
    const donationName = "Donated by @" + userHandle;
    fetch(url, {
      method: "POST",
      body: {
        donationAmount: donation,
        donationName: donationName,
      },
    })
      .then(??)
      .catch((e) => {
        console.log(e);
      });
  };

What's the correct way of sending the parameters and opening the Stripe checkout page with the custom data I'm sending?