Netcomm router setup

Hey there,

Easy setup at device level but I'm looking for instructions to set up at router level to apply to all device on the home network. This to block certain sites for kids. 

The router is a Netcomm  NF18ACV. With a fairly recent firmware, being NC2-R6B014.EN

All instructions I could find online point to firmware V1 and the later version do not seem to have an option to tweak DNS ?