Question AR Foundation with ARKit - place object in front of the camera

Hi..
I am trying to develop an AR app as part of my thesis. I m working with AR Foundation and ARKit on Unity. To place objects on tap I am using a C# Script that I found on github (have attached the script I m working with with the thread). I am trying to create a portal and I want it to appear in front of the camera when the user taps on the device screen. Right now, it just appears sideways sort of like i am already inside the portal. As I m new to unity and C#, I would like some help on how to always have the portal appear in the front of the camera so that the user can enter it.