Every Podpage website comes with SSL — the security protocol that encrypts the connection between your visitors' browsers and your site (that's the padlock in the address bar). When you connect a custom domain, we issue a free SSL certificate for it automatically.
There's nothing for you to set up. As soon as your domain's DNS is pointed at Podpage, we start issuing the certificate. During setup you might briefly see a security error when visiting your site — that's normal. Podpage sets up HTTPS automatically once your domain connects; this usually takes less than an hour.
Tip: Haven't connected your domain yet? See how to connect your domain name to your Podpage.