On the group’s “SETTINGS” screen, towards the lower right, there is a slide control to “Enable Join Code”: slide that control to the right, and click the “SAVE” button (towards the upper right), to enable generation and use of a join code for the group. A join code will be displayed at the lower right; when you’re ready to have your students join your class group, you’ll return to the “SETTINGS” screen to see and make a note of this group join code so that you can pass it on to your students!
Also at the group’s “SETTINGS” screen, consider whether you wish to set the “Group Type” of the group to “MODERATED” rather than (the default) “PRIVATE”. (Class groups generally are not set “PUBLIC” for reasons of privacy; furthermore, licensed curriculum modules cannot be assigned to “PUBLIC” groups.) The choice is up to you.
A “MODERATED” group’s existence, and your role as owner of the group, will be visible in the Polar Cloud under the “PUBLIC GROUPS” display. Then non-members who go to the group’s non-member “SUMMARY” screen may click on the “JOIN” button to generate a notification request to join the group – a request that will go to you as group owner to “ACCEPT” or “DECLINE”. Thus a “MODERATED” group allows general Polar Cloud members to see the existence of, and request to join, your class group.
In contrast, a “PRIVATE” group is only visible to its own members, under the “MY GROUPS” display; neither its existence, nor your role as its owner, will be visible to non-members.
Neither type of group allows non-group-members to see who (besides you, as owner) is in the class group: non-group-members will not be able to see your student members of the class group.
If you’d like the fact that you have a class doing 3D printing via the Polar Cloud to be visible in the Polar Cloud – perhaps you’d like to hear from other teachers doing 3D printing to collaborate with them – then you may wish to set your class to “MODERATED” rather than “PRIVATE” type.