Where do I add the DNS records?

At the company that manages your domain’s DNS, which is usually where you bought the domain (GoDaddy, Namecheap, Squarespace, Cloudflare, and so on). In Sending DNS Setup, if your domain is not on Cloudflare, Podspun reads your domain’s settings and names the company for you, with a link to open its control panel. Sign in there, find your domain, open its DNS settings, and add the rows shown. If your domain is on Cloudflare, use the “Add everything to Cloudflare for me” button and it writes them for you. If it is at Dynadot, the page lists Dynadot’s own steps, including the ANAME it uses for the domain itself.

Each Host is shown the way most DNS companies ask for it: the part before your domain (www), and @ for the domain itself. Click a Host or Value to copy it. If your DNS company wants the full name, add your domain to the end.