One DNS record does it. At your registrar (GoDaddy, Namecheap, wherever your domain lives), add an A record pointing your domain at our server — the exact value and a walkthrough are on the connect your domain page.
Until the record is in place your slice waits patiently in dormant mode; once DNS points at us, we detect it automatically, switch the site on, and issue HTTPS — usually within minutes of the record propagating.
Subdomains of our house domain (you.aihaslanded.com) need no setup at all — they're live the moment your slice is.