How to get my Client ID?

To get your Client ID, you have to visit https://dev.twitch.tv/console/apps/create and register your application. Don't worry, you don't need your own application. In this case, the Twitch API Request Tool will be your application. The following information are required:

Field Description
Name Feel free to choose any name you like!
OAuth Redirect URL You have to add the following: http://tart.retro-elite.de/index.html
Category Should be: Website Integration

Now you should be redirected to your application management page where you can find your Client-ID! It is a string of random alphanumeric characters. Copy this string back to the TART and put it in the field "Client ID".

How to get my User Access Token

To get your User Access Token, first of all you need a Client ID. You don't have a Client ID yet? Go back to "How to get my Client ID?" and start over. Otherwise, you simply have to press the "Generate" button next to your Client ID. You will be redirected to an authentication site of Twitch to confirm your granted access. The scopes you have selected define the level of access.

What are scopes?

To execute some of the requests, you need special privileges. These are defined by the scopes you choose from the scope selection. After you choose your scopes, you have to generate a new Access Token!

Validate my Access Token?

You can validate your Access Token and check, which Client ID is associated with this token and which scopes are active.

Revoke my Access Token?

Your Access Token should be treated like a password! Never give anybody access to your access token you don't trust. Therefore it is good practice to revoke your access token after you finished testing around!

I don't trust you but would like to use TART?

No problem, just visit the GitHub repository and take a look at the source. Feel free to download the project and execute it local on your own machine. The complete project is written in javascript, your browser should have no problems to run it. Keep in mind you have to make some changes to the source to run it local!
It is not ok to host TART online on any other platform without permission! So be nice and ask.

If you think, there are any shady additions to the other files, you can download them from their representative developer:

Name + Version Website
Bootstrap 4.3.1 https://www.bootstrapcdn.com/
bootstrap-select 1.13.10 https://developer.snapappointments.com/bootstrap-select/
BsMultiSelect 0.2.22 https://github.com/DashboardCode/BsMultiSelect
jQuery 3.4.1 https://jquery.com/
popper 1.15.0 https://popper.js.org/

Disclaimer

The Twitch API Request Tool is an unofficial tool to request the Twitch API. It is by no means associated with Twitch!