Backup Beeping Alarm in Cabin of SR

I have an issue I am trying to resolve in my 2017 Toyota Tacoma SR former work truck. Every time I place the truck in reverse it starts beeping inside the cabin of my truck (not on the outside). I am trying to figure out how to disable the beeping but on my truck there is nowhere on the radio/navigation setting that mentions a backup beeper. Also, there is no button on the truck that indicates a beeper. I am wondering if there is a way for me to disengage a wire to stop this or if anyone has a remedy to stop this annoying beeping sound when I place my truck in reverse?

 

Wonder if it’s an add on…

 

Me too, I’ve read a few threads that suggest an add on that could be done by the company that had the truck as a precautionary measure to let the driver know they were in reverse? However, I don’t know where this would be considering it is not anywhere obvious considering I’ve looked all in the cabin of my truck. Seriously has me at dismay as to where they would have installed this. I doubt it would be a complicated install considering how simple the beeping is?

 

Apply parking brake,turn switch on,put in reverse and find the beeper.
It may be connected to the reverse lights

 

Apply what switch?

 

I’m assuming it beeps key on ,engine off in reverse?