A captive portal is the branded page a guest sees before they get online. It is where you introduce your brand, ask for consent and (optionally) collect a contact detail — the start of the customer profile.

Steps

Connect your access points to oneCDP (most captive-portal-capable hardware works).
Brand the portal: logo, colours, a short welcome and an optional promo.
Choose a sign-in method: email, SMS code or social login.
Add a clear consent checkbox describing what data you collect and why.
Publish, and start seeing visits flow into profiles.

Good practice

Keep the portal fast and the ask small. A single email field with explicit consent converts far better than a long form, and gives you a clean, lawful basis to communicate later.