Blender 2.79 won't insert keyframe I am following a guide for the Grease Pencil, however I cannot add keyframes as per step 2?

I hover the mouse cursor over the Dope Sheet and select All Channels. Nothing seems to happen.

I then select Grease Pencil Draw, however I am unable to draw.
Here is the setup for a frame by frame animation.

Check Continuous Draw and Onion Skin.

After you draw something, move to the next frame and hit  D , then  B . This will create an Empty Frame where you can draw something else.