Shipping Address Emails

I have a billing address and a shipping address for one customer. I want to input both, but he only has the one email (obviously). The system wont let me add a shipping address w/o an email address. There is no button that says “use the billing email…”

Does anyone know?

Why not just use their billing email as the shipping email?

Try that open on one of your contacts and let me know. Mine gives me an “error” saying email is already in use. But you cannot save and move forward without an email