Every site has a free address that stays yours for good: borgsites.com/s/yourname. You do not need a domain to publish.
Already own a domain, like yourbusiness.com? Open Domains in your account, go to Connect a domain you already own, type it in and send it. A real person replies by email with the exact records to add where your domain is registered, and we connect it for you.
Do not have one yet? See Buy a domain.