Custom channels help

[kingpinjimi12345]

Is there a "for idiots" guide to setting up custom channels? I just cant seem to wrap my head around this. I am follwoing the steps on the help section and tried adding one of the example webcam things on the " Example M3U Playlist" on the main page but it just keep getting this error.

invalid source url: failed to retrieve m3u: 404 Not Found

[tmm1]

Stream format: HLS

Source: Text

#EXTM3U
#EXTINF:-1,Camera
https://......./master.m3u8

XMLTV should be blank