Parental Controls?

I have Xfinity Internet and Xfinity Mobile. But all the instructions I find seem to be for TV. I'm looking for a way through the Xfinity Gateway to block certain things. But I go into the Xfinity app... I can "pause" Internet connections that use my Wi-Fi. But I am unable to "block" websites and games (Roblox) for my 9 year old. 

Am I correct?