It has been a number of decades since I had ducks, but no one else is answering and I'nm sure they will correct me if I tell you something incorrect.
I went to town earlier and got a larger old school thermometer. I also got a 15 watt bulb to try instead of using the 25 watt suggested in the YouTube videos.
So, when I got home I did some prep work and some tinkering. I poked and few holes in the sides, made an aluminum barrier to put between the light bulb and the eggs so that there wouldn't be so much direct heat. I very carefully and quickly added the new thermometer, changed out the light bulb and put in the barrier. I'm still working with my humidity level, but it's staying around 50% and my temp is staying around 99°F. The highest it's gotten is 100 and the lowest it's gotten is 97 97 is low; you want to strive to keep the temperature close to 100. Are these Temps ok? What range do I need to stay in? Also, how many times a day do I need to mist them with water I misted duck eggs only at lockdown? Is the air cell supposed to be at the large end of the egg Yes or the small pointy end of the egg No I wanna make sure I'm looking at them right..lol!