First you need to point your domain to Confetti through your domain provider. If you are not familiar with setting up domains we recommend you to send this article to you domain provider.
Subdomains (www e.g.) - Most common and recommended!
For subdomains you add a CNAME record from www.yourevent.com to cname.confetti.events (replace with your domain and the address to your event). Then you navigate to Settings -> Setup, scroll down to URL and add www.yourevent.com to the event.
A naked domain is the domain without www or similar in front of it, i.e. yourevent.com. It works a bit different and can't be used with CNAME on all domain providers. Some providers allow you to add a CNAME or ALIAS record for your domain. In that case you point it to cname.confetti.events just as mentioned above, and then add yourevent.com to Confetti. If your provider doesn't allow this handling of naked domains the best solution is to make yourevent.com redirect to a subdomain of your choice, like www.yourevent.com.
One easy way to make yourevent.com redirect to www.yourevent.com is to point an A-record to 126.96.36.199 which will handle this automatically.
Read more here: http://wwwizer.com/naked-domain-redirect
Important: Don't put Confetti in an iframe to handle the support the named domain. This will have unpredictable results. When you click th signup-button the url should change to yourevent.com/signup, if not, you're probably using the iframe "solution".
Setting one of your domains to primary means that yourevent.confetti.events will always redirect the visitor to www.yourdomain.com.