player hits a key and creates a primitive

I would like to know how I can get it so, if my player clicks the “g” key that a primitive (cube, sphere etc.) appears in game on the ground in front of him. Even more so, a premade model instead of a primitive. Thanks

Yeah, simply like this.

public GameObject go;

void Update() 
    { 
        if (Input.GetKeyDown("g"))
        {
            Instantiate(go, Vector3.zero, Quaternion.identity);
        }
    }