You need the original Hackbar v1.3.5 or the "HackBar XSS" variant. Search GitHub for "Hackbar XUL" or "Hackbar Legacy." Look for the file with the .xpi extension. Do not download the modern WebExt version.
In essence, the Cyberfox Hackbar is a that lives inside your browser, providing quick access to encoding tools, database-specific payloads, and HTTP request manipulation. cyberfox hackbar
Find a Cyberfox-compatible Hackbar XPI from a trusted repository like GitHub. Install via Add-ons Manager: Open Cyberfox and press Ctrl + Shift + A . Drag and drop your .xpi file into the window. Restart the browser when prompted. You need the original Hackbar v1