How can I slowly rotate a sprite to face its movement direction?

I’m just starting out with all of this & this is a super basic question, but I haven’t been able to find a solution that works anywhere.

I have a 2d sprite which moves around using the in-built physics system & I need it to face the direction it’s moving, but I need it to rotate around slowly not just turn instantly.

Here’s the script as it stands in case that helps:

public float movespeed;

private Rigidbody2D rb2d;

void Start()
    rb2d = GetComponent<Rigidbody2D>();

void FixedUpdate()
    float moveHorizontal = Input.GetAxis("Horizontal");
    float moveVertical = Input.GetAxis("Vertical");
    Vector2 movement = new Vector2(moveHorizontal, moveVertical);
    rb2d.AddForce(movement * movespeed);

Thanks in advance for the help

Try this :

IEnumerator Rotator()
        Quaternion targetRotation = Quaternion.LookRotation(movementDirection);
        Quaternion currentRotation = transform.rotation;
        for (float i = 0; i < 1.0f; i += Time.deltaTime / timeToRotate)
            transform.rotation = Quaternion.Lerp(currentRotation,targetRotation,i);
            yield return null;

Here timeToRotate is total time in which you want to rotate sprite to movement direction