The employee has the right to a lunch break from 30 minutes to two hours. The exact duration must be specified in the employer’s internal work regulations.
This time is not considered working time and is not paid, so you can leave your workplace. But if the employee cannot leave due to the specifics of the work, the employer must provide the opportunity to have lunch during working hours and pay for the break.
You cannot leave without permission: if something disappears in the sales area without you, you will be held responsible. If the employer does not provide the opportunity to have lunch, you can complain about him, for example, to the labor inspectorate.