The Problem:

By default, whenever the employee module is used in point of sale, Odoo only allows employees with attached system user access to close an ongoing point of sale session. Thus, you either have to make all cashiers system users (which, if you have numerous employees, will increase your subscription cost for the enterprise edition) or let the cashiers wait for a system user to close their session (which may not be desirable if your cashier don't report to anyone before closing the day).

The Solution:

This module makes it possible for each non-system user employee to close their point of sale sessions.