How to wait for the canvas fade in out to finish before saving the game?

this script make a canvas group alpha to change between 0 and 1 :

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;

public class Description : MonoBehaviour
{
    public Canvas canvas;
    public AnimationCurve animationCurve;
    public float fadingSpeed = 5f;
    
    public TMP_InputField _inputField;

    public enum Direction { FadeIn, FadeOut };

    private CanvasGroup canvasGroup;

    void Start()
    {
        if (canvas == null) canvas = GetComponent<Canvas>();
        canvasGroup = canvas.GetComponent<CanvasGroup>();
        if (canvasGroup == null) Debug.LogError("Please assign a canvas group to the canvas!");

        if (animationCurve.length == 0)
        {
            Debug.Log("Animation curve not assigned: Create a default animation curve");
            animationCurve = AnimationCurve.EaseInOut(0f, 0f, 1f, 1f);
        }
    }

    public void StartFading(bool InOut)
    {
        if (canvasGroup != null)
        {
            if (InOut)
            {
                StartCoroutine(FadeCanvas(canvasGroup, Direction.FadeIn, fadingSpeed));
            }
            else
            {
                StartCoroutine(FadeCanvas(canvasGroup, Direction.FadeOut, fadingSpeed));
            }
        }
    }

    public IEnumerator FadeCanvas(CanvasGroup canvasGroup, Direction direction, float duration)
    {
        var startTime = Time.time;
        var endTime = Time.time + duration;
        var elapsedTime = 0f;

        if (direction == Direction.FadeIn) canvasGroup.alpha = animationCurve.Evaluate(0f);
        else canvasGroup.alpha = animationCurve.Evaluate(1f);

        while (Time.time <= endTime)
        {
            elapsedTime = Time.time - startTime;
            var percentage = 1 / (duration / elapsedTime);
            if ((direction == Direction.FadeOut)) // if we are fading out
            {
                canvasGroup.alpha = animationCurve.Evaluate(1f - percentage);
            }
            else
            {
                canvasGroup.alpha = animationCurve.Evaluate(percentage);
            }

            yield return new WaitForEndOfFrame();
        }

        if (direction == Direction.FadeIn) canvasGroup.alpha = animationCurve.Evaluate(1f);
        else canvasGroup.alpha = animationCurve.Evaluate(0f);

        _inputField.readOnly = false;
    }
}

and using it :

using UnityEngine;
using System.Collections;
using System.IO;

public class SavingGame : MonoBehaviour
{
    public int resWidth = 1920;
    public int resHeight = 1080;
    public SaveLoad saveLoad;
    public Description description;

    private static int countName;

    private void Start()
    {
        countName = 0;

        string[] dirs = Directory.GetDirectories(Application.persistentDataPath + "\\" + "Saved Screenshots",
            "*.*", SearchOption.TopDirectoryOnly);

        if(dirs.Length > 0)
        {
            countName = dirs.Length;
        }
    }

    public static string ScreenShotName(int width, int height)
    {
        return string.Format("{0}/Saved Screenshots/SaveSlot{1} SavedGameSlot_{2}x{3}_{4}/SavedGameSlot_{1}x{2}_{3}.png",
            Application.persistentDataPath,
            countName,
            width, height, System.DateTime.Now.ToString("yyyy-MM-dd_HH-mm-ss"));
    }

    void Update()
    {
        if (Input.GetKeyDown("k"))
        {
            description.StartFading(true);
        }
    }

    public void Save()
    {
        description.StartFading(false);

        string filename = ScreenShotName(resWidth, resHeight);
        string directory = Path.GetDirectoryName(filename);
        Directory.CreateDirectory(directory);
        ScreenCapture.CaptureScreenshot(filename);
        StartCoroutine(saveLoad.SaveWithTime(directory, Path.GetFileNameWithoutExtension(filename) + ".savegame.txt"));

        countName++;
    }
}

I'm calling the Save method through the editor ui button onclick event.

the problem is before saving i want first the fading out of the canvas to be finished and then making the rest of the saving code in the Save method :

public void Save()
        {
            description.StartFading(false);

i want that after finished the StartFading then to make the saving :

string filename = ScreenShotName(resWidth, resHeight);
            string directory = Path.GetDirectoryName(filename);
            Directory.CreateDirectory(directory);
            ScreenCapture.CaptureScreenshot(filename);
            StartCoroutine(saveLoad.SaveWithTime(directory, Path.GetFileNameWithoutExtension(filename) + ".savegame.txt"));
    
            countName++;

not sure how to do it. using a while maybe in the Save method ?