New Input System Adding more to it

I'm using the new input system which I think is just awesome, however in my game I need the character to be able to climb a ledge and with the new input system, i have no idea how to implement that kind of script or action. I tried a google search for a simple climb script but when I implement it, a consol error comes up saying "Character Controller.Move called on inactive Controller?

here is the script I'm trying to use.

Transform chController; bool inside = false; float heightFactor = 3.2f;

 private CharacterController FPSInput;

 void Start()
 {
     FPSInput = GetComponent<CharacterController>();
 }

 void OnTriggerEnter(Collider Col)
 {
     if (Col.gameObject.tag == "Ledge")
     {
         FPSInput.enabled = false;
         inside = !inside;
     }
 }

 void OnTriggerExit(Collider Col)
 {
     if (Col.gameObject.tag == "Ledge")
     {
         FPSInput.enabled = true;
         inside = !inside;
     }
 }

 void Update()
 {
     if (inside == true && Input.GetKey("Jump"))
     {
         chController.transform.position += Vector3.up / heightFactor;
     }
 }

its not a perfect script for what i want but its a start if i can just get it to work. I would much prefer to use the Invector Asset Package but I cant afford it so my only choice is to make the script from scratch or hopefully someone here can help me.