If you try downloading videos from Twitch, especially channels that require a subscription, you will quickly find out that it's not possible with 3rd party programs like DVDFab Downloader or Twitch Leecher. This is because Twitch has decided to block API tokens of such apps from accessing content. Presumably under the guise of copyright. If interested you can read about how it unfolded here: [URL]https://github.com/Franiac/TwitchLeecher/issues/419[/URL]
However, I found a workaround that mitigates the problem, albeit in a "dirty" "hacky" way as the author Franiac puts it. What it involves is using the last version of Twitch Leecher to have Twitch account authorization (Version 1.7.3) you can download it here: [URL]https://github.com/Franiac/TwitchLeecher/releases/tag/v1.7.3[/URL]
Once installed simply authorize your Twitch account by clicking the box with a Twitch icon.
[ATTACH=CONFIG]13678[/ATTACH]
Click on the Connect with Twitch tab.
[ATTACH=CONFIG]13679[/ATTACH]
Then enter your username and password.
[ATTACH=CONFIG]13680[/ATTACH]
It will then ask for a 2-Factor-Authorization code that will be sent to your email used for your Twitch account.
[ATTACH=CONFIG]13681[/ATTACH] Once you enter the code correctly you'll need to Authorize TwitchLeecher.
[ATTACH=CONFIG]13682[/ATTACH]
You will now see a green box with a tick meaning your Twitch account is authorized.
[ATTACH=CONFIG]13683[/ATTACH]
So from here just search for the video you want to download using URL. But before you click download you need to Disconnect TwitchLeecher in your Twitch Settings here: [URL]https://www.twitch.tv/settings/connections[/URL]
[ATTACH=CONFIG]13684[/ATTACH]
You will know if you're successful when you click download you'll see the following screen.
[ATTACH=CONFIG]13685[/ATTACH]
Otherwise you see the following error screen.
[ATTACH=CONFIG]13686[/ATTACH]
So there you have it. Yes it's a PITA having to re-login and authorize every time you want to download a sub-only video but at least it works, for now. Note that version 1.8.0 removed the ability to authorize your Twitch account, hence why I'm using 1.7.3 and the author of the software doesn't expect things to change with how Twitch handles 3rd party API tokens.
Hope this information is useful.8)