Get a client secret when the amount is zero

I use the Payment Element to allow people to sign up for my service. I create an intent like this:

const subscription = await stripe.subscriptions.create({    customer: customer.id,    items: [{ price }],    // Tell stripe we don't have the card details yet.    payment_behavior: "default_incomplete",    payment_settings: { save_default_payment_method: "on_subscription" },    expand: ["latest_invoice.payment_intent"],    coupon: coupon || undefined,  });

This works great and I get a client secret to then render the payments element, however if I offer a discount code, which make the initial payment 0, this call does not give me a client secret, since there is "no invoice to pay". Is there any way to get a client secret and offer coupon codes that make the first payment 0?