---
title: "Comment by Yudhi Setiawan on \"Build a chatbot in 20 minutes using Flutter and Dialogflow\" | Hashnode"
description: "Hello brother, thank you for the tutorial. I'm following the steps above, but I got this error E/flutter ( 5219): [ERROR:flutter/lib/ui/ui_dart_state.cc(148"
url: "https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4"
---

[Discussion](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400)

Comment [Build a chatbot in 20 minutes using Flutter and Dialogflow](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400)

[Yudhi Setiawan](https://hashnode.com/@yudhizth)

[Jul 18, 2019](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4)

Hello brother, thank you for the tutorial. I'm following the steps above, but I got this error `E/flutter ( 5219): [ERROR:flutter/lib/ui/ui_dart_state.cc(148)] Unhandled Exception: NoSuchMethodError: The method '[]' was called on null.`

![Annotation 2019-07-18 200022.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1563455158371/ExqOEQmvB.png)

[Promise Amadi](https://hashnode.com/@promise)

[Jul 18, 2019](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4#reply-5d3087e8d5d9a94b3b4d5aea)

can you push your project to GitHub, so that I can go through your source code and see where the error is coming from.

[Thomas Hasler](https://hashnode.com/@TBS)

[Jul 30, 2019](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4#reply-5d402d3c9894947334625789)

I am facing same issue . Can you please tell while creating service account which role should I select for the new service account?? Please Help I need to include this chatbot in my projects as soon as possible!. Thanks in advance!!

[Yudhi Setiawan](https://hashnode.com/@yudhizth)

[Jul 30, 2019](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4#reply-5d4032229894947334625790)

[Promise Amadi](https://hashnode.com/@promise) sure, this is the GitLab project link [gitlab.com/yudhizth/chatbot.git](https://gitlab.com/yudhizth/chatbot.git)

[Promise Amadi](https://hashnode.com/@promise)

[Jul 30, 2019](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4#reply-5d409953436c914c158f878b)

Hi [Yudhi Setiawan](https://hashnode.com/@yudhizth), the source code is on Github and this is the link [github.com/Wizpna/chatbot](https://github.com/Wizpna/chatbot)

[Yudhi Setiawan](https://hashnode.com/@yudhizth)

[Jul 31, 2019](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4#reply-5d417b127351d76731cd78e5)

Hi [Promise Amadi](https://hashnode.com/@promise) your code is working. Thank you

[Thomas Hasler](https://hashnode.com/@TBS)

[Jul 31, 2019](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4#reply-5d4182adb4f847bd59310a11)

Your project is working and I think i have problem in credentials part can you please tell which role should i select while creating new service account?? for downloading json file! Thanks!!

[Yudhi Setiawan](https://hashnode.com/@yudhizth)

[Jul 31, 2019](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4#reply-5d419ea1aa10ff7154afa2b2)

Hi Thomas, I got the same problem previously, and then I try to create a new credential with this role: Dialogflow -> Dialogflow API Admin [Thomas Hasler](https://hashnode.com/@TBS)

[Thomas Hasler](https://hashnode.com/@TBS)

[Jul 31, 2019](https://hashnode.com/posts/build-a-chatbot-in-20-minutes-using-flutter-and-dialogflow/5d2d72c36d8e5e5323656400/comment/5d306ec6d5d9a94b3b4d5ac4#reply-5d41c719aa10ff7154afa3c9)

I got it working in my emulator but its not working in my mobile device , not getting any reply from bot!!