No overload for method `ZoomOrthoCamera' takes `0' arguments (basic programming question)

I am probably getting this error due to my lack of programming knowledge, but I am trying to impliment a zoom-to-mouse function. But after adding it in under Update() I get the error in the title.

private void ZoomOrthoCamera(Vector3 zoomTowards, float amount)
{
    *snip*
}

I add it to Update:

void Update () {
	if(player.hooman) {
		ZoomOrthoCamera();

I believe the issue is that I do not have any arguments in ZoomOrthoCamera(). I tried adding some that I thought where relevant, but just got different errors. What exactly am I supposed to be throwing in there?

Well, the declaration says that ZoomOrthoCamera() needs a Vector3 and a float in order to work. I guess that the Vector3 is the location where the camera needs to move towards, and the amount is how close to that position to get, possibly with 0 meaning don’t move and 1.0 meaning move all the way.