The following files are firmware images that should work on most ESP32-C3-based boards with 4MiB of flash, including WROOM and MINI modules, that use the revision 3 silicon (or newer).
USB serial/JTAG support is enabled on pin 18 and 19. Note that this is not a full USB stack, the C3 just provides a CDC/ACM class serial and JTAG interface.
Program your board using the esptool.py program, found here.
If you are putting MicroPython on your board for the first time then you should first erase the entire flash using:
esptool.py --chip esp32c3 --port /dev/ttyUSB0 erase_flash
From then on program the firmware starting at address 0x0:
esptool.py --chip esp32c3 --port /dev/ttyUSB0 --baud 460800 write_flash -z 0x0 esp32c3-20220117-v1.18.bin