Move the player based on the camera's rotation

I am trying to change my script for a 3d platformer to make it so the player moves forward based on the rotation of the camera and the change i made was this.

transform.Translate(Vector3.back * Time.deltaTime * speed ,GetComponent.().WorldToViewportPoint);

I am getting an error for no appropriate version of ‘UnityEngine.Transform.Translate’.

What part of this do i need to change to get it to work?

Try transform.Translate(Vector3.back x Time.deltaTime x speed, Camera.main.transform);