Users can join groups much more easily now! Site managers can enable the ‘Group Quick Join’ per group type to make sure that users can join a group with one click (confirmation step is removed). Site managers can also create CTA links (call-to-action) on landing pages that allow users to join (non-closed) groups in a single click.
The group quick join settings can be found via the site manager dashboard.
If you want users to join a group directly through a button you created elsewhere, for example on landing pages, just add [group url]/join as the link of the button. For example, if the group's URL is: /group/1, then quick join link will be: /group/1/join.
TIP: just hover over the button and copy the URL that appears in the bottom left corner of your Chrome internet browser: