Help with a Hornblaster on my '19 F150

My 15 year old son got me a Hornblasters Flatlaw 3L Train Horn Kit (part# HK-F3B-M3) for Christmas. He wants to install it with me, but the directions were pretty vague. I am looking for some help from anyone who has installed something similar on a 2019 F150. I am looking to install all of this either under the truck or under the hood - I don’t want to install anything in the bed. Can anyone help me out? Looking for decent mounting points, where/how to run wiring, etc.

Hey buddy, I’ve got a Nathan 5 chime on my 2019. I did custom wiring and mounting brackets. I have pictures as well as drawings. If you still need them lemme know.