Not necessarily. You can try the advanced settings. Therefore you need to know a little bit more about the technology used. The gadget retrieves motion jpeg (mjpeg) images from cameras. It does that via a URL that looks a bit like this
Where the username and password stands there will be the real username and password of the camera. Then an @ sign and the IP address of the camera wich is 192.168.1.50 in this example. It ends with the address suffix. In this example that is /cgi-bin/video.jpg. This suffix is different from vendor to vendor and most of the time you can find it in the manual / documentation of your camera.