Welcome!
Check out the "performance" section for information around tuners and such:
https://www.ecodieselram.com/forum/forums/ecodiesel-performance.28/
The most economical route is to find one from a lower mileage wreck.. sites like car-part.com is a good resource.
Newer motors are much more than that.. some have reporting upwards of almost 15K for a brand new engine.
Welcome... we've got a lot of members here with 2020+ trucks. So far some decent feedback.. granted all are newer trucks and a smaller sample size, so time will tell!
..or you can buy a OBD reader on Amazon. Example:
https://www.amazon.com/OBDLink-Bluetooth-Professional-Grade-Diagnostic-Performance/dp/B07JFRFJG6/
Alpha OBD is the most recommended one as it can do so much more.