You can also consider Microsoft Family Safety if your router doesn't have the functionality already mentioned. It may require you getting a little less soft (I'm a father and I recommend you do that anyway ) to add him to your family, but once that's done I believe the rest takes care of itself.
Good luck!
it is a windows 10 pc.I am single father and its got to the point where i cant take it no more.Since lockdown he has been in front of the pc 24 /7.I am a softy so he gets away with it but no no.lol
Good luck!