Can't open dialogue box when pressing button

Hey hello,

I am currently following the Unity Dialogue & Quest course on Udemy, still a bit of a beginner. In the lecture you can open the dialog when pressing the mouse button. However am making a game on mobile and want to implement a UI Button where the player can click to talk on.

However I currently have not found a solution on how to implement the button to open the dialogue. The transparent white box is the button this is the code:

public bool OpenDialagueButton(PlayerController callingController) {

         dialogueButton.onClick.AddListener(() =>
         {
             callingController.GetComponent<PlayerConversant>().StartDialogue(dialogue);
         });

         return true;
     }

PlayerConversant playerConversant;

public void StartDialogue(Dialogue newDialogue) { currentDialogue = newDialogue; currentNode = currentDialogue.GetRootNode(); onConversationUpdated(); }