MenuSizeChangerFunction() function in Update();

// THIS IS EXAMPLE 1
// Resize with MenuSizeChangerFunction() function in Update();

// create UI Panel in Unity Editor with size 2200, 1100, call it "menuInventoryPanel".
// creat script for this UI Panel called "inventoryMenuScript" and copy this code there.
// create Button in Unity Editor, in "On Click()" editor add new element and atache "menuInventoryPanel" and choose "inventoryMenuScript > InventoryInteraction0" as function.

using UnityEngine;
using UnityEngine.UI;

public class inventoryMenuScript : MonoBehaviour
{
    public Vector2 desiredMenuSize;
    
    public float lerpTimer = 0f;

    public bool lerpTimerChecker = false;
    public bool inventoryMenuSizeChanger = false;
    public bool inventoryMenuResizingInProgress = false;

    void Start ()
    {
        this.GetComponent<RectTransform>().pivot = new Vector2(0.5f, 0.5f);
        this.GetComponent<RectTransform>().anchorMin = new Vector2(0.5f, 0.5f);
        this.GetComponent<RectTransform>().anchorMax = new Vector2(0.5f, 0.5f);
        this.GetComponent<RectTransform>().anchoredPosition = new Vector2(0f, 0f);
        this.GetComponent<RectTransform>().sizeDelta = new Vector2(1760f, 880f);
    }

    void Update()
    {
        if (inventoryMenuResizingInProgress) // if true then resize this element
        {
            MenuSizeChangerFunction(this.GetComponent<RectTransform>().sizeDelta, desiredMenuSize);
        }
    }

    public void InventoryInteraction()
    {
        lerpTimer = 0; // reset lerpTimer which is referenced as 3rd variable of Lerp
        MenuSizeVariable(); // if clicked then change desired deltaSize variable
        inventoryMenuResizingInProgress = true; // if clicked then start process of resizing at Update();
    }

    void MenuSizeVariable() // function to change desired target size on button click
    {
        if (!inventoryMenuSizeChanger)
        {
            desiredMenuSize = new Vector2(2200f, 1100f);
        }
        else
        {
            desiredMenuSize = new Vector2(1760f, 880f);
        }

        inventoryMenuSizeChanger = !inventoryMenuSizeChanger;
    }

    void MenuSizeChangerFunction(Vector2 sizeCurrent, Vector2 sizeNew) // function to change size of the element with Vector2.Lerpd
    {
        if (lerpTimer < 1)
        {
            lerpTimer += Time.deltaTime;
            this.GetComponent<RectTransform>().sizeDelta = Vector2.Lerp(sizeCurrent, sizeNew, lerpTimer);
        }
        else
        {
            inventoryMenuResizingInProgress = false;
            lerpTimer = 0;
        }
    }
}