Draw line On one Axis

How can i Draw the Line on the z Axis and change when the character move when character move when i wrote this it goes Down?

Debug.DrawLine(transform.position , Vector3.forward , Color.blue , 1000);

Debug.DrawLine( transform.position, transform.forward, Color.blue, 1000 );

Vector3.forward is describing a direction in World-Space, transform.forward is in Local-Space (relative to the transform’s orientation)