Plug the power back in. The indicator light (if available) should begin flashing rapidly, indicating the update is in progress.
Unplug the power from your TV or controller board. Insert USB: Plug the drive into the board's USB port.
Extract the downloaded .rar file and copy the .bin firmware file directly to the root directory of the USB drive (do not put it in a folder).
Once the light stops flashing or changes color, unplug the USB drive and restart the device.
Ensure the firmware matches your specific panel voltage (3.3V, 5V, or 12V) to avoid damaging the hardware. USB Bridge Firmware updates - tubbutec
Usually provided as a .bin file inside a .rar or .zip archive. How to Install via USB