Unfortunately, you cannot just add
https:// to the URL for a domain and expect it to work. Only websites which have SSL certificates can be served via
https://. Fireside itself has a SSL certificate, as does all of its subdomains (like yourpodcast.fireside.fm), so they are served securely via
https://. Just adding your custom domain to Fireside doesn’t create a SSL certificate for it.
Fortunately, we have developed a (free!) SSL certificate acquisition and integration feature for customers with custom domains. Just flip the toggle switch in your Domains section to turn it on.