How do I save a .txt file in a certain folder

I want to save the .txt file in a folder outside of the game files

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using System.IO;
 using System;
 using UnityEngine.UI;
 public class BackUp : MonoBehaviour
 {
 public float bTatos;
 public float b;

 public Controller con;
 public bool can = false;

 private void Update()
 {
     if(can == true)
     {
         con = null;
     }
     else
     {
         con = GetComponent<Controller>();
     }
 }
 public void Load()
 {
     can = true;
 }
 public void BackUps()
 {
     if (can == false)
     {
         bTatos = con.tatos;
     }
     string path = Application.persistentDataPath + "/Log.txt";

this is the part where it saves it to a certain folder, and I want to know how to change it to /storage/emulated/0/Download/Log.txt, or something like that.

     if (can == false)
     {
         string content = bTatos + "\n";
         if (!File.Exists(path))
         {
             File.WriteAllText(path, content);
         }
         File.WriteAllText(path, content);
     }
     string text = File.ReadAllText(path);
     b = float.Parse(text);
     if (can == true)
     {
         con.tatos = b;
         can = false;
     }
 }

}