The board is accessible from the top, remove the keycaps and find six screws, open them and carefully slide the board out. Note the USB-C port sticks out a bit and is in the way for the board to go out, you'll need to tilt it.
The board has a BYK903 marked chip which I have yet to identify.
There is an ISP port nearby with 6 pins that can be used to read and write the firmware with https://github.com/gashtaan/sinowealth-8051-dumper I haven't tried but looking at other boards on the net with a similar configuration it's a safe assumption.
I didn't identify any way to reset the board by pins so the only way to do it is with the USB protocol, this can be done with https://github.com/carlossless/sinowealth-kb-tool with which I successfully read the firmware but didn't really try to analyze it yet.
The firmware when read never gets more than 32K of data, the rest are zeros so this is most likely an SH68F881, but this is still just a guess.