A knowledge base article about How do I direct prospective members to join my bConnected List (Google Group)? provided by the UC Berkeley IT Service Hub - Knowledge Portal
If you want to embed a “subscribe here” link on a website, or share a direct link for prospective list members to subscribe to your list, the following address will work: https://groups.google.com/a/lists.berkeley.edu/d/forum/samplelist. Remember to exchange “samplelist” for your list’s name, and leave off “@lists.berkeley.edu” in the URL.
The prospective member will either see a “Join Group” button, or “Apply for Membership” depending on how your list is set up.