Is there a way to restrict bandwidth for certain websites because I'm struggling to find anything relating to this?

If so, could someone provide a pointer?

Thanks

For certain websites i am not sure but in general if you want to use bandwidth management you need to go at
-Firewall > Filter Setup > Filter Rule (top left)
-press Add (for new rule)
you will see >
-User Management or Bandwidth Limit (BW Limit)
tick which one you need, then will appear
-UCF (URL Content Filter)

Is set to None with no options ... Not sure if needs to pay for service to appear other options or is just missing other options from the firmware
(current firmware 1.2.0.1)

EDIT
Never used these features but ... it may be helpful if you know the web IP address want to block then maybe set it via Source Address or Destination Address etc ... so have a go around