add and remove matches

so im new to a ammo system and not sure how add to the code I have. so basically I'm trying have the character be able to pick up a pack of matches and it add to the display on the screen then when you light a candle the display number goes down

I have a script to pick up matches, light candles, and a ui script (for stamina and health) I just need to know what i need to add

UI Script

 using System.Collections;
 using System.Collections.Generic;
 using TMPro;
 using UnityEngine;
 
 public class UIScript : MonoBehaviour
 {
     [SerializeField] private TextMeshProUGUI healthText = default;
     [SerializeField] private TextMeshProUGUI staminaText = default;
     private void OnEnable()
     {
         FirstPerson.OnDamage += UpdateHealth;
         FirstPerson.OnHeal += UpdateHealth;
         FirstPerson.OnStaminaChange += UpdateStamina;
     }
 
     private void OnDisable()
     {
         FirstPerson.OnDamage -= UpdateHealth;
         FirstPerson.OnHeal -= UpdateHealth;
         FirstPerson.OnStaminaChange -= UpdateStamina;
     }
 
     private void Start()
     {
         UpdateHealth(100);
         UpdateStamina(100);
     }
 
     private void UpdateHealth(float currentHealth)
     {
         healthText.text = currentHealth.ToString("00");
     }
 
     private void UpdateStamina(float currentStamina)
     {
         staminaText.text = currentStamina.ToString("00");
     }
 }

pick up match

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class pickupmatch : MonoBehaviour
 {
     public Text txt;//text 
     public GameObject match;
 
     void OnTriggerStay(Collider target)
     {
         if (target.tag == "Player")
         {
             if (Input.GetKeyDown(KeyCode.E) && tlamp.activeInHierarchy == true)
             {
                 txt.text = " ";
                 match.SetActive(false);
             }
         }
     }
 
     private void OnTriggerEnter(Collider coll)//entrance and exit to/from trigger 
     {
         if ((coll.tag == "Player") && tlamp.activeInHierarchy == true)
         {
             txt.text = "E Pick Up match";
         }
     }
     private void OnTriggerExit(Collider coll)//entrance and exit to/from trigger 
     {
         if (coll.tag == "Player")
         {
             txt.text = " ";
         }
     }
 }

light a candle

 using UnityEngine;
 using UnityEngine.UI;
 
 public class lightacandle : MonoBehaviour
 {
     public Text txt;//text 
     public GameObject fire1;
 
     void OnTriggerStay(Collider target)
     {
         if (target.tag == "Player")
         {
             if (Input.GetKeyDown(KeyCode.E))
             {
                 txt.text = " ";
                 fire1.SetActive(true);
             }
         }
     }
 
     private void OnTriggerEnter(Collider coll)//entrance and exit to/from trigger 
     {
         if ((coll.tag == "Player")  && fire1.activeInHierarchy == false)
         {
             txt.text = "E to light";
         }
     }
     private void OnTriggerExit(Collider coll)//entrance and exit to/from trigger 
     {
         if (coll.tag == "Player")
         {
             txt.text = " ";
         }
     }
 }