To allow all group participants to invite new users, firstly create a group (see here how to do it) or direct yourself to an already created group.

Next, click on the Information button to access to all the details of the group.

In the participants section, enable the All group participants can invite others button.

Now all the participants of the group will be able to invite to the group to other users.

To allow all group participants to invite new users, firstly create a group (see here how to do it) or direct yourself to an already created group.

Next, click on the name of the group to access to all the group details.

In the participants section, enable the All group participants can invite others button.

Now all the participants of the group will be able to invite to the group to other users.