player isnt moving based on rotation unity velocity rigidbody code example

Example 1: set rotation to velocity unity

transform.rotation = Quaternion.LookRotation(rigidbody.velocity);

Example 2: unity how to set rigidbody velocity

Vector3 velocity = new Vector3(10f/*x*/, 10f/*y*/, 10f/*z*/);
GetComponent<Rigidbody>().velocity = velocity;