Parental Controls Help

I have the DG2460 model. Below is what my user settings look like when logged in to the parental controls section.

I wanted to set up keyword filtering along with websites to keep kids off and away from certain things/sites. According to the user guide for this device there SHOULD be a section there that says keyword filtering and there is not.

Is there a way to get this feature with an update or something?? Or another way I can put keyword filtering in place?