I’ve posted two videos below. One from top position and one from bottom so you can see how to make the choke work when you’re in control and when you’re not.
Here’s the choke from side control top and knee on belly as shown by CUFF lightweight champion Bruce Lutchmedial.
Source: Ben Stark
Here’s the choke from when you’re on the bottom and your opponent has you in side control. It’s a great video by the guys at Red Schafer Mixed martial arts. They’ve included some great grip variations.