The chain could be too tight or there's something wrong in the transmission

Did you check to see that it has spark at the spark plug

It could be your accelerator pedal. Your accelerator pedal has a sensor on it. I believe that truck is drive by wire. I will check that first. Secondly it could be the throttle body. The throttle body is electronic and it has a motor inside that controls the throttle flap. Try unplugging your accelerator pedal and then crank it up if it goes back to idle then it's the pedal. And if you can get it to a OBD2 scanner see what codes is throwing

I'm pretty sure he's talking about the Polaris Trailblazer 250. Have you figured out your problem yet?

Did you check the fuses , battery cables and key switch

Yess thank you! it was the fuse next to the battery, but now It’s cranking but no start