On this page - https://groups.io/helpcenter/ownersmanual/1/inviting-people-to-join-a-group/sending-invitations-to-join-the-group

The first paragraph - In the left navigation menu on the group’s website, select Admin > Invite. The Invite page appears. If you have created an Invite notice for the group and set it to be the Active Message, the text of that notice appears in the Customize Message panel.

The hyperlink for Invite notice is wrong - it goes to Group Sponsorship Notice, rather than Invite Notice.
https://groups.io/helpcenter/ownersmanual/1/managing-member-notices/group-sponsorship-notice

Should be 
https://groups.io/helpcenter/ownersmanual/1/managing-member-notices/invite-notice

Frances

Oops, sorry about that link error. I corrected it.

Thanks, Frances!

- Nina