How to increase jump force depending on the amount of time that the screen is pushed?

I want to have a function in which it determines how long the screen has been pushed and than adjusts the jump force based on it. I got the script from Sample Assets so i have no idea how to add the functions without causing a 1000 errors at the same time, can somebody help (Sorry I'm a noob)

 using UnityEngine;
 
 namespace UnitySampleAssets._2D
 {
     
     public class Character2D : MonoBehaviour
     {
         private bool facingRight = true; // For determining which way the player is currently facing.
         
         [SerializeField] private float maxSpeed = 10f; // The fastest the player can travel in the x axis.
         [SerializeField] private float jumpForce = 400f; // Amount of force added when the player jumps.    
         
         [Range(0, 1)] [SerializeField] private float crouchSpeed = .36f;
         // Amount of maxSpeed applied to crouching movement. 1 = 100%
         
         [SerializeField] private bool airControl = false; // Whether or not a player can steer while jumping;
         [SerializeField] private LayerMask whatIsGround; // A mask determining what is ground to the character
         
         private Transform groundCheck; // A position marking where to check if the player is grounded.
         private float groundedRadius = .2f; // Radius of the overlap circle to determine if grounded
         private bool grounded = false; // Whether or not the player is grounded.
         private Transform ceilingCheck; // A position marking where to check for ceilings
         private float ceilingRadius = .01f; // Radius of the overlap circle to determine if the player can stand up
         private Animator anim; // Reference to the player's animator component.
         
 
 
         private void Awake()
         {
             // Setting up references.
             groundCheck = transform.Find("GroundCheck");
             ceilingCheck = transform.Find("CeilingCheck");
             anim = GetComponent<Animator>();
         }
         
         
         private void FixedUpdate()
         {
             // The player is grounded if a circlecast to the groundcheck position hits anything designated as ground
             grounded = Physics2D.OverlapCircle(groundCheck.position, groundedRadius, whatIsGround);
             anim.SetBool("Ground", grounded);
             
             // Set the vertical animation
             anim.SetFloat("vSpeed", GetComponent<Rigidbody2D>().velocity.y);
         }
         
         
         public void Move(float move, bool crouch, bool jump)
         {
             
             
             // If crouching, check to see if the character can stand up
             if (!crouch && anim.GetBool("Crouch"))
             {
                 // If the character has a ceiling preventing them from standing up, keep them crouching
                 if (Physics2D.OverlapCircle(ceilingCheck.position, ceilingRadius, whatIsGround))
                     crouch = true;
             }
             
             // Set whether or not the character is crouching in the animator
             anim.SetBool("Crouch", crouch);
             
             //only control the player if grounded or airControl is turned on
             if (grounded || airControl)
             {
                 // Reduce the speed if crouching by the crouchSpeed multiplier
                 move = (crouch ? move*crouchSpeed : move);
                 
                 // The Speed animator parameter is set to the absolute value of the horizontal input.
                 anim.SetFloat("Speed", Mathf.Abs(move));
                 
                 // Move the character
                 GetComponent<Rigidbody2D>().velocity = new Vector2(move*maxSpeed, GetComponent<Rigidbody2D>().velocity.y);
                 
                 // If the input is moving the player right and the player is facing left...
                 if (move > 0 && !facingRight)
                     // ... flip the player.
                     Flip();
                 // Otherwise if the input is moving the player left and the player is facing right...
                 else if (move < 0 && facingRight)
                     // ... flip the player.
                     Flip();
             }
             // If the player should jump...
             if (grounded && jump && anim.GetBool("Ground"))
             {
                 // Add a vertical force to the player.
                 grounded = false;
                 anim.SetBool("Ground", false);
                 GetComponent<Rigidbody2D>().AddForce(new Vector2(0f, jumpForce));
             }
         }
         
         private void Flip()
         {
             // Switch the way the player is labelled as facing.
             facingRight = !facingRight;
             
             // Multiply the player's x local scale by -1.
             Vector3 theScale = transform.localScale;
             theScale.x *= -1;
             transform.localScale = theScale;
         }
     }
 }
 

File #2

 using UnityEngine;
 using UnitySampleAssets.CrossPlatformInput;
 
 namespace UnitySampleAssets._2D
 {
     
     [RequireComponent(typeof (Character2D))]
     public class Control : MonoBehaviour
     {
         private Character2D character;
         private bool jump;
         
         private void Awake()
         {
             character = GetComponent<Character2D>();
         }
         
         private void Update()
         {
             if(!jump)
                 // Read the jump input in Update so button presses aren't missed.
                 jump = CrossPlatformInputManager.GetButtonDown("Jump");
         }
         
         private void FixedUpdate()
         {
             // Read the inputs.
             bool crouch = Input.GetKey(KeyCode.LeftControl);
             float h = CrossPlatformInputManager.GetAxis("Horizontal");
             // Pass all parameters to the character control script.
             character.Move(h, crouch, jump);
             jump = false;
         }
     }
 }