How to restrict inputting key while the object rotating

Hello everyone I am making a fortune wheel spinning kind of thing and when I tap the key rapidly the wheel keeps spinning and spinning.

How can I make it available to input only when the wheel stops?

Here’s my script for the roulette

public class RouletteController : MonoBehaviour
{
    float rotSpeed = 0;
    
    // Start is called before the first frame update
    void Start()
    {
        Application.targetFrameRate = 60;
    }

    // Update is called once per frame
    void Update()
    {                
        if (Input.GetMouseButtonDown(0))
        {
            this.rotSpeed = 10;
        }

        transform.Rotate(0, 0, this.rotSpeed);

        this.rotSpeed *= 0.99f; 
    }
}

Add a Boolean variable useInput set it to false when wheel starts spinning and set it to true when wheel stops spinning. Now where you are checking for input, simply add a check if (useInput). This will ensure that wheel only receives input when it stops spinning