In order to update the fimrware you will need a
USB to Serial Converter Windows PC Board name PR50-31 Note : if the file name has any special char please remove it
How to put in program mode
press and hold CFG button press and release the RST button while holding the CFG button release the CFG button go to the folder and click on "Run" The command promt will open, enter the serial port number there
Make sure the PC has usb-srila driver https://www.silabs.com/developers/usb-to-uart-bridge-vcp-drivers?tab=downloads