Need Help with APM to CHDK Camera Link Tutorial

I am setting up a Quad copter for Aerial Photogrammetry. This is my first project.
I am using Ardu copter 3.0.1 with the APM 2.62.
The trouble I am having is that when I get to the part in this tutorial for setting parameters, I find that I do not have the RELAY_PIN parameter or the CAM_TRIGG_DIST parameter in my FULL PARAMETER LIST in Mission Planner.

Can someone please help me with this? Is this an outdated tutorial? is there a new way that this is done?
I noticed that the tutorial is referencing an older version of firmware, and Mission planner.

Thank you!

I think the CAM_TRIGG_DIST parameter is new for AC3.1. Luckily it’s now released!