Available to admins is the manage users and invitations area in the admin menu in the top right corner (capital letter of the first letter of your account name) of your account.
Admins can invite new users in the invitations area and manage see accepted, unopened and expired invitations
Admins can also see active users, change user roles or suspend users in the admin manage users area.
To Invite a new user, admins can navigate to the Admin menu > Invitations > 'Invite New User'
Check out our short video below for more detail: