Hxc-fw-installer.hex -

is a "bootloader installer". It must be flashed directly to the Gotek's internal STM32 or AT32 chip using a serial connection.

This article provides a deep dive into what this file is, why it is essential, and a step-by-step guide to using the Hxc-fw-installer.hex to successfully flash (or re-flash) your HxC hardware. Hxc-fw-installer.hex

file depends on your hardware (STM32 or Artery AT32 based Goteks) and the cable you are using: is a "bootloader installer"