plugin for channel 4 won't detect the video

[www.channel4.com]

when downloading , FreeRapid only get the web page done.

Yes, that URL pattern is not supported yet. I can't watch it in my browser, it requires registration. But from the debugger, it seems they are using adobe HDS, and perhaps with DRM. If that is the case, then unfortunately it's not supported.

Yeah, Channel 4 switched to HDS with DRM years ago. Unfortunately it can't be supported.