I got a code that isn't normalized. Can someone help me?

here’s my code:

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

public class Move : MonoBehaviour
{
Vector3 Position = new Vector3(1.0f, 1.0f, -25.0f);
const int SPEED = 5;
// Use this for initialization
void Start ()
{

}

// Update is called once per frame
void Update()
{
    if (Input.GetKey("w"))
    {
        Position += new Vector3(0, SPEED * Time.fixedDeltaTime, 0);
    }
    if (Input.GetKey("s"))
    {
        Position += new Vector3(0, -SPEED * Time.fixedDeltaTime, 0);
    }
    if (Input.GetKey("a"))
    {
        Position += new Vector3(-SPEED * Time.fixedDeltaTime, 0, 0);
    }
    if (Input.GetKey("d"))
    {
        Position += new Vector3(SPEED * Time.fixedDeltaTime, 0, 0);
    }
    transform.position = Position;
    

}

}

Naturally Time.fixedDeltaTime is the difference between two calls of FixedUpdate() and it always holds the same value.

As you see, it would make no sense using Time.fixedDeltaTime in the Update() method.
Better use Time.deltaTime instead in Update().
Time.deltaTime is the time interval between current frame and the last one, which is the same than the time interval between two calls to the Update() method.