Apple on a mobile device
Copy the RSS feed URL from your email invitation
In the Apple Podcasts app, tap Library
Click Edit and select Add a Show by URL
Paste the URL in the field and tap Follow
Apple on a laptop or desk top computer
Copy the RSS feed URL from your email invitation
In the Apple Podcast desktop app, click File > and select Add a Show by URL from the menu
Paste the URL into the field and click Follow