Install Arduino IDE with stm32 support follow this how-to

Identify which version of the board you have, This article helps you with it.

Download firmware for your HW version without bootloader, there are two versions, standard (no serial port support) and one with debug information written into the serial port (use in case you have some specific problem with your module)

versions without serial port support, most people need this version:

firmware binary for v1 and v2 boards

firmware binary for v3 boards

firmware binary for v4 boards

versions with serial port enabled, for debug purposes:

firmware binary for v1 and v2 boards

firmware binary for v3 boards

firmware binary for v4 boards

Connecting the module to the computer

Then you need to connect the module to the computer USB port, module has a 4pin terminal marked USB:

You can solder USB cable directly to the module, or use long Dupont male terminal for a temporary connection. If the connection is not successful try swapping data lines cables.

TODO: investigate true connections for D+ and D- and make notes here!

After you downloader firmware and have Arduino installed with support for stm32duino, and your module is recognised by your OS as serial port or modem device, open command prompt or shell in case of linux/macos and navigate to folder where is your downloaded firmware (probably something like c:\Users{USER}\Downloads). Then execute this command to upload firmware:

for linux:

${HOME}/.arduino15/packages/stm32duino/tools/stm32tools/2021.5.31/linux/maple_upload ttyACM0 2 1EAF:0003 ./current_no_serial_usb_HWv1-2.bin

for windows:

 C:\Users\{username}\Documents\ArduinoData\packages\stm32duino\tools\stm32tools\2021.5.31\linux\maple_upload.bat ttyACM0 2 1EAF:0003 /current_no_serial_usb_HWv1-2.bin