Trying to access components of a prefab

I have a UI element that I want to dynamically add panels to. The panel is a prefab with two text fields inside it.

I created a class for the prefab, and the two text components are assigned to it in the inspector :

 using UnityEngine;
 using UnityEngine.UI;
 using System.Collections;
 
 public class ListController : MonoBehaviour {
 
     public Text TextName, TextDescription;
 
 }

I then have a function which can instantiate the prefab, but im not able to access the components?

     void myFunction()
     {
         GameObject newItemInList = Instantiate( myPrefab ) as GameObject;
         ListController controller = newItemInList.GetComponent();
         controller.TextName.text = "foo";
         controller.TextDescription.text = "bar";
     }

Apparently this is not an acceptable usage of GetComponent(); ? Ive written it this way cause I saw it used like this in a tutorial, only mine is saying GetComponent in this context "cannot be inferred from the usage"