Add an icon to the address bar

Hi.
Is it possible to add an icon to the address bar, similar to how it is done in https://addons.mozilla.org/en-US/firefox/addon/crxviewer/ ?

<img width="1307" height="197" alt="Image" src="https://github.com/user-attachments/assets/89dde74d-1a70-40a4-a591-af2bbd7a441e" />