To connect your Live channel to an actual Live Video stream you will need to setup a streaming source.
Open the CMS and go to Admin < Streaming Sources.
click on New.
enter a name for your streaming source, This will not be shown to users.
Add your Streaming URL for every platform.
The next step is to select the streaming source you created from your Live Channel.
click in the MS on Live > Select your channel > Settings.
Scroll down to the Streaming Sources section and select the streaming source you created.
Once you click on Update the streaming source you created will be connected to the Live channel.
You can create as many streaming sources as needed and select them for different channels.
There is also an option to choose a streaming source for a specific Program.
Inside the Program settings screen there will be Streaming Source Override option -
You can select a streaming source different then the default for the channel.