If your extension on Twitch is not loading, the most likely reason is you haven’t Granted Permission / Linked your Identity to the extension yet. The extension should have prompted you for this on the first load, but in case it didn’t and you no longer see the message you can do so manually by following these steps.
On a browser/desktop when viewing a Twitch stream, there will be a Crowd Control icon on the right-hand side of the video player. Hover over it, and click it. You’ll then see “Manage Access”, click that, and then finally click “Grant” on the Manage Permissions page.
On mobile/iOS/Android you should see a “Grant Permissions” button when first loading the extension. If you don’t, you can manually grant permissions by clicking the 3 vertical dots next to “Crowd Control”, then Link Identity, and then click Confirm on the message dialog that pops up.
After doing that, you should now be able to view the extension and send effects. If you still are unable to see or load the extension, make sure you do not have anything like FFZ or BetterTwitchTV blocking extensions or anything similar.