libretiny/docs/ota/flashing.md

It is possible to upload firmware binaries manually, using the command-line tool ltchiptool. For this, you need the .uf2 file generated after compilation (usually found in .pio/build/my_board/).

1. Install Python. Afterwards, run pip install ltchiptool.
2. ltchiptool uf2 upload my_firmware.uf2 uart COM96 (replace my_firmware.uf2 with your file name and COM96 with your upload port).