Chains aren't supposed to go on 20" wheeels
Check page 626 of your owners manual. There is no approved chain type for 20" wheels.
I contacted Chrysler Customer Care and this was their response:
Vehicle Description: RAM 2500 LARAMIE 4X4
Hi Mr. XXXXX, This is Carina from Ram Customer Care. Here is the information you requested. On 4x4 2500 model trucks, the use of class “U” snow chains is permitted on the rear wheels only of trucks equipped with LT245/70R17E, LT265/70R18E or LT275/70R18E tires. Do not use tire chains on the rear wheels of 2500 4X4 model trucks equipped with LT285/60R20E tires. There may not be adequate clearance for the chains and you are risking structural or body damage to your vehicle. We do not have any recommendations for alternatives. The customer may want to refer to the internet for alternatives (ex. Spikes Spider, etc.). The dealership may also be able to advise alternatives. Thank you and have a great day!