Changing the tire size on my 2023 5th gen sport

[Joesey76]

I recently put a lift and 35 inch tires on my truck. I can't find an answer on changing the tire size so my speedo works properly. I talked to dodge and they told my I had to buy a speedometer calibrater for $400 CAN. I booked it in, cable doesn't fit the new fully digital dash. I'd really like to fix it. I'm 6km/hr out at 100km/hr.