Other users are right, it's not a sidebar. Try to go to settings to see if you can enable sidebar mode, it has some "Premium Features" link, and doesn't explain anything. Did not even try to use app since it's a separate window outside the browser.

Well, it really does not work as a sidebar. I use latest version of extension and firefox. But this extension does not use firefox sidebar functions, it tries to improvise similar functions separately, but it creates incompatibility issues and will not work on different setups, including mine with tiled windows.
So, isn't usable for me, which is sad. Also there is not much configuration.

Very good! As an additional feature request, could we have the option to open the window in a new tab? That would be much more useful.

does not open as sidebar

The extension doesn't appear as a sidebar, but as a new window that blocks content on the screen.

The best AI extension. Allow fast access as sidebar to Copilot, ChatGPT, Google Gemini and much more!

Open AI ChatGPT, Microsoft Copilot and Google Gemini in a single App as sidebar. Really awesome!

Beznadziejne, po prostu otwiera nowe okno z dostępem do klientów AI. Dziękuje bardzo, tyle to sam mogę.

works like a charm with very low latency.