cannot convert `UnityEngine.Transform' expression to type `UnityEngine.Quaternion'

the error happens in this part of my code but it works fine in a tutorial i was watching

void Update ()
{
	

    if(target == null)
    {

        return;
    }
    Vector3 dir = target.position - transform.position;

    Quaternion lookRotation = Quaternion.LookRotation(dir);

    Vector3 rotation = Quaternion.Lerp(PartToRotate, lookRotation, Time.deltaTime*trunspeed).eulerAngles;

    PartToRotate.rotation = Quaternion.Euler(0f, rotation.y, 0f);
}

Replace this line:

Vector3 rotation = Quaternion.Lerp(PartToRotate.rotation, lookRotation, Time.deltaTime*trunspeed).eulerAngles;

Missed “.rotation”