Siri Intent Suggested Invocation Phrase not displaying in ShortcutViewController - swift

Question

I'm trying to enable a simple Siri Intent for my iOS app, with a TableView cell functioning to invoke INUIAddVoiceShortcutViewController, with the TableView as its delegate. However, the suggested invocation phrase that is supposed to display on the controller view, does not.
I'm extremely new to Swift, and so I haven't tried much else as I do not know what to try
The invoking function is:
getSiriView() {
intent.suggestedInvocationPhrase = "Get a joke"
let siriView = INUIAddVoiceShortcutViewController(shortcut: INShortcut(intent: intent)!)
siriView.delegate = self;
self.present(siriView, animated: true, completion: nil)
}
and its delegate extensions are as follows:
//
// ViewControllerSiriExtensions.swift
// Helium
//
// Created by Richard Robinson on 2019-04-26.
// Copyright © 2019 Richard Robinson. All rights reserved.
//
import Foundation
import IntentsUI
extension TableViewController: INUIAddVoiceShortcutButtonDelegate {
func present(_ addVoiceShortcutViewController: INUIAddVoiceShortcutViewController, for addVoiceShortcutButton: INUIAddVoiceShortcutButton) {
addVoiceShortcutViewController.delegate = self
addVoiceShortcutViewController.modalPresentationStyle = .formSheet
present(addVoiceShortcutViewController, animated: true, completion: nil)
}
func present(_ editVoiceShortcutViewController: INUIEditVoiceShortcutViewController, for addVoiceShortcutButton: INUIAddVoiceShortcutButton) {
editVoiceShortcutViewController.delegate = self
editVoiceShortcutViewController.modalPresentationStyle = .formSheet
present(editVoiceShortcutViewController, animated: true, completion: nil)
}
}
extension TableViewController: INUIAddVoiceShortcutViewControllerDelegate {
public func addVoiceShortcutViewController(_ controller: INUIAddVoiceShortcutViewController, didFinishWith voiceShortcut: INVoiceShortcut?, error: Error?) {
controller.dismiss(animated: true, completion: nil)
}
public func addVoiceShortcutViewControllerDidCancel(_ controller: INUIAddVoiceShortcutViewController) {
controller.dismiss(animated: true, completion: nil)
}
}
extension TableViewController: INUIEditVoiceShortcutViewControllerDelegate {
public func editVoiceShortcutViewController(_ controller: INUIEditVoiceShortcutViewController, didUpdate voiceShortcut: INVoiceShortcut?, error: Error?) {
controller.dismiss(animated: true, completion: nil)
}
public func editVoiceShortcutViewController(_ controller: INUIEditVoiceShortcutViewController, didDeleteVoiceShortcutWithIdentifier deletedVoiceShortcutIdentifier: UUID) {
controller.dismiss(animated: true, completion: nil)
}
public func editVoiceShortcutViewControllerDidCancel(_ controller: INUIEditVoiceShortcutViewController) {
controller.dismiss(animated: true, completion: nil)
}
}
extension TableViewController {
public var intent: JokeIntent {
return JokeIntent()
}
}
Currently, the controller appears and works properly, except it does not display the suggested phrase.