Educational institutions owners (I.e. school administrators) have the facility to assign purchased licences to their organisation's users. For a user to be part of an organisation you need to invite them as explained in this article: How educational institutions users are managed.
To assign a licence to a user or more, you need to go to the Licences section of the organisation and then on the tab Acquired. Once in the licence section press on the licence from the three dot button and tick each user that you want to assign or unassign the licence from.
When a user is assigned to a license, they will just inherit access to all those oBooks grouped in the license until the license expiry date.
See it in action