Beginner's questions about DNS


I am under 23.05.0 on ZyXEL WSM20, and I was wondering how I can easily configure the following in LUCI:

  1. force the router and all the clients connected (ethernet + wifi) to use custom DNS
  2. is it possible to force the use of DNS over HTTPS instead of plain DNS, for the purpose of 1)?
  3. if I connect a device with a client VPN (which uses the VPN DNS), would it work, or that cause a conflict?

Thank you in advance

might need to enforce it by implementing

you can, assuming task(s) from 1 are fulfilled

somone/thing connecting to the openwrt device from outside ? no