How to handle a domestic worker's night shift allowance -
how much, to be paid in monetary terms, or be offset against time?

Domestic worker works ordinary eight hours per day (08:00 to 17:00), from Monday to Friday.
Domestic worker works from 19:00 to 20:00 on Mondays to Thursdays. It is not clear
whether normal time of one-and-half hours off, (like 15:00 to 16:00; as well as 16:30 to 17:00)
can be offset against the hour overtime (19:00 to 20:00), or against the night shift allowance?
If it is either of the two, must the other be paid then?

To clarify, if normal one-and-half hours is taken off for the overtime hour, must the night shift
allowance be paid? Is the allowance ten percent of the ordinary daily wage?
If normal one-and-half hours is taken off for the night shift allowance, must the hour overtime be paid?
Is the overtime hour then calculated at one-and-half the normal hourly wage tariff?

Thank you so much for your help.