Default Prism Launcher with Google Voice Search.

Ok so I have not used a HTC device in about 4 years so I know a lot has change. But i just came from a Moto X and I am used to the OK Google commands. Is there a way I can use voice search from the homescreen with prism launcher? I have Google now turn on in Google settings but nothing happens. Is there an xposed module or should I just install GEL