Yes. It needs to be enabled in the configuration, accessible for the address range, and not blocked by firewall rules. The following CLI command will show if it is enabled, the port and allowed addresses:
Also note that for the default configuration webfig is NOT accessible from the WAN port (e.g. ether1 on a RB7xx series router). So make sure that your PC is plugged into one of the LAN ports (ether2 - ether5).