How to keep the old line text?

I have been trying to figure out this but with no success . What I am trying to do is to keep the old text while the script adds the new text below the old text.

     public GameObject Text_Object;
         private Text textComponent;
 void Start () {
         //gets the text UI Object in canvas component
         textComponent = Text_Object.GetComponent<Text>();
                 textComponent.text = "Hello";
                 Text2();
     }
 
 void Text2(){
 textComponent.text = "Hey";
 }

Basically as you can see the first text gets replace with the second text. What I'm trying to do keep the old text while if I press T it prints the new text below the old text and also add a command when they hit D it clears the text new and old text.