On a Roku, how do I stream Cox channels I pay for

I have Cox digital and a Roku.  I have managed to get some of the Discovery and History channels to stream on my Roku..Not live tv.. Yet other channels will not stream.  Such as Boomerang cartoon channel, CBS live, ABC live, etc., that I pay for, through Cox.  How do I get these channels to link to my Roku through my Cox account without having to pay additional fees for the channel?  Is there a way to stream ALL Cox channels on the Roku?  Is there a Cox Contour app for Roku? Thanks in advance for any, useful, help.