https://www.youtube.com/watch?v=Aek8GJ-0B1o&t=108s

go to 192.168.1.1 (it’s on the back of your router) the user name is admin and the password is either admin or just password then get their IP and put it in the mac filter section. The loction varies depending on your router but you will find it.

Get the other people mac addresses from the "active clients list" and the add them in "access control list" and there choose "deny listed"

If you know their MAC addresses you can block them out specifically, if you do not you can make it so that your device can use it... Search for filtering Mac addresses on Google

Netcut doesn't work for me

Mannnn just use natcut

Netcut app nw ene m tekorechebetlwe be mnm liyaku ayechelum