The App Token is used to get twitch data that don't need an authentication. For example to get a profile picture of a Twitch User or to subscribe to the EventSub API.
Without the App Token "OpenOverlay" will not work.
Enable openoverlay.webhook.twitch.app_token.regenerate in config/openoverlay.php
<?php
return [
'webhook' => [
'twitch' => [
'app_token' => [
'regenerate' => true,
Make sure following redirect URL is added to your Twitch Application
https://{YOUR_URL}/connection/app-token/callback
Domain need a valid SSL certificate.
Visit following page of your OpenOverlay system
https://{YOUR_URL}/connection/app-token/redirect
Add the given hash to your .env file
OVERLAY_TWITCH_APP_TOKEN={HASH}
Make sure to copy the full hash