You can connect a registration and ticket sales service to your event website at any time via Manage event > Registration > Registration provider. We offer special integration with events using Eventbrite. If you use any other services, choose "Other services" and add your direct link. This will add a button for Registration to your event website.
If want to use an external service and have not yet set it up, you can submit your event with the option "No registration" and simply add it later.
Read more about "How do I use Eventbrite with Conferize?"