Go get two rolls of paper towels, two cans of carb cleaner, a good air gun with a long tip, a bright flashlight and a small inspection mirror, hopefully on the end of a telescopic handle.
Mop up every bit of diesel you can in the valley, spray the rest with carb cleaner and blow off everything with compressed air. Removing the Y pipe and hump hoses between the turbo and intakes will help you get to the tight areas beneath the fuel bowl.
Get it spotless/dry, then start the truck and use your flashlight and mirror to see where the leak starts. It might not leak at idle, in which case you can have a friend hold the idle at an elevated speed and keep looking. Then, after it doesn’t leak again, take it for a drive and it will leak when you aren’t looking at it and the valley will be all wet and you can start over.
The stock fuel bowl has many, many places to leak. I removed and resealed fuel bowl, changed everything hose and clamp, and still had a tough time finding an intermittent fuel leak. My fuel restriction sensor would actually leak through the body of the sensor (not the threads) and only when it was under load. I put a brass plug in it but only after I pulled the bowl no less than half a dozen times.
Good luck. I believe the stock fuel bowl leaking makes a lot of folks go the e-fuel route.