Visit https://github.com/opentrack/opentrack and download the latest stable release of OpenTrack:
then run the installer. Once finished, run opentrack.exe and pin it to your taskbar. You will need to run the program every time you start playing Nuclear Option.

Once opened, you should see this screen:
Make sure that you have these same options chosen for input, output, and filter. Test whether your webcam is working with OT by clicking Start. You should see your fat, greasy, ugly face with pimples and dead skin all over it with a wire-frame box around it. On the right side of the window you should see an Epic & Cool Octopus shadowing the movements of your ugly, fat head.

Run the game itself and, in the controls menu, check this box:
and test it out in a free flight or something.

The tracker will work fine this way but the default mapping curves are linear, so turning your fat head 90 degrees in the cockpit will mean that you can't see your monitor in real IRL. Click on mapping and adjust the sensitivity curves for both pitch and yaw to be closer to this:
A shallower curve from 0-180 will allow for finer freelooking across a greater range while a steeper curve like the one above allows for both fine control around the nose of the aircraft yet enough gain to look directly behind/above for keeping an eye on biologically male discord users trying to 2-circle with me.

In the shortcuts tab, you should really only ever need three inputs:
All three of these should be placed on very convenient keys/buttons because, while very reliable during normal use, OT will 𝔰𝔥𝔦𝔱 𝔦𝔱𝔰𝔢𝔩𝔣 if you ever break line of sight with your webcam and usually the only way to fix it is to stop and restart tracking.

The filter tab will let you jack the smoothing up which can alleviate stuttering when in low-light/goblin-esque conditions.

In the lower right corner of the output tab you can add a few centimeters to the default depth and height of your digitally represented, fat, ugly head within the cockpit.
I wouldn't crank these up 2 far tho cuz something like Y=12/Z=10 will look nice like this in a Chicane:
but like this in a Medusa: