There are a couple ways I can think of…. Depending on what you are going for?
You could run a line over from the park lights and have the DRL’s trigger when the park lights are on. This would accomplish the goal of having them on in park. I would also diode isolate the circuit to prevent back feeding. (if you don’t he DRL’s will also trigger the park lights)
You could also trigger them on from a toggle switch but I would suggest running switched power to the toggle, as you will inevitably leave them on someday.
If you just want them on all the time (as long as the truck is running) there are several switched ignition sources under the hood, just tap one of them.