The official Windows utility used to push firmware from a PC to an Amlogic-powered device. Version 2.1.6 or higher is recommended for the S912 chip.
If you need help identifying your exact board variation, please tell me the or the current build number listed in your device settings. I can then help you locate the exact firmware image and flashing utility for your specific device. Share public link tx9 pro android tv box firmware link
Always scan downloaded .img or .zip files with VirusTotal before flashing. The official Windows utility used to push firmware