You missed the page? No problem. Follow these steps to get back on track.
Go to your ScaleTrack admin page, select Domains, and click Add Domain.
Type your desired address (e.g., go.mysite.com). Do not use http/https.
ScaleTrack will generate a unique target value (e.g., <id>.domains.scaletrack.com). Copy this value.
Login to your DNS provider (GoDaddy, Namecheap, Cloudflare) and create a new record using the data shown on the right.
You cannot use a root domain (e.g., mysite.com). You must use a subdomain (e.g., track.mysite.com).