Most clones will ship with either slcan or candlelight and will be plug and play rendering this section null.
However if you would like to try a different firmware for troubleshooting, you can webflash these boards using the following webpage (requires Chrome or Edge)
If you encounter issues with the device not being recognised or being write restricted follow the links they have for fixing Windows Drivers, or if on Linux adding a udev rule.
Note, the clones may not have a button for instance the jumpers for the MKS Canable, MKS Canable Pro are highlightedin the below image.
Note: The same page can flash slcan firmware on the device also!