In Brave browser settings under: brave://settings/security - there is an option to choose a DNS provider (Use Secure DNS) under Advanced. I have chosen the Clean Browsing parental filter DNS and need this DNS to be LOCKED so nobody on the computer can change this setting and access bad sites.
Is there any possible way we can do this? Like in terminal, group policy ect…?
Thank you! 
Some DNS reference material:
Re locking out other users’ adjustments to DNS settings . . .
In the Mac OS System Preferences > Network > locations and their DNS settings, as an admin level user of the Mac, you can manually set the DNS server numbers.
Thanks! The problem with setting it up in network settings on Mac is that a VPN overrides them, but if I set the DNS up in Brave itself, VPN doesn’t override. I use a VPN so it must also work with VPN
Maybe contact your VPN service and ask them, if they have DNS servers “for privacy and security of my family.”
I manually enter the DNS servers, and currently use something like:
77.77.77.7 (VPN primary DNS)
77.77.77.8 (VPN secondary DNS)
33.33.33.22 (Wi-Fi DNS)
In that order. I am able to connect to the Wi-Fi network, and also visit the Internet.