New Chromecast can't install channels

I just got the new Chromecast, but when I search for channels and go to it's listing on the store there is no toggle to download it. Is there something I need to toggle or is it not supported at this time? I am enlisted in the beta channel if that matters.

This is some sort of bug in the Play Store.

You can hit install in a browser on and select your Chromecast

Hi Edwin:
Could you please supply more detail on this successful install if it differs from tmm1 solution that follows.
Thanks in advance.