@Yvonne_Carlson are you saying that you want your viewers to be able to watch your events on Roku, Apple TV or ChromeCast? This is more of a function of your streaming provider than the ChOP platform. ChOP only displays an embedded video from another source, that other source would have to output to the devices you mentioned.
If someone has a chromecast they can cast the tab that ChOP is open in their browser but that is not a function of ChOP but the browser and the Chromecast plugin.
does that help at all?