You'll need a trailer to haul propane. A Google search will find you one. Purchase propane at the COOP and pull in front of the propane tank at the farm to fill it. Once it is full, stand in front of the tank and hit the key to "manage production". Once at the menu, you will need to change the propane tank from "storing" to "distributing" and give it a few hours in-game time. It will distribute propane to each bin. When you put wet corn in the bin using an auger, you need to stand in front of the bin and access its production menu. In that menu you need to activate the dryer to start drying corn. You will see how much propane, wet corn, and dry corn you have in that menu as well.
Viewing post in FS25 - Ray County, Missouri comments
This is the truck google suggests.
https://www.kingmods.net/en/fs25/mods/59512/freightliner-m2-stakebed-autoload
It's a flatbed.