If you are working for a Set-Top Box manufacturer, you must obtain the tools through the official channel.
Assuming you have a legitimate need and a compatible STB, follow this guide. (Note: Replace generic steps with exact file names if you have obtained the tool via official channels.) availink stb developer tool download
Pinout guide: Most Availink STBs have a 4-pin header (GND, TX, RX, VCC). If you are working for a Set-Top Box