Note it’s not a normal JTAG, you need to flash the MCU directly by contacting the pins (SOIC clip). Also unfortunately, the MCU is on the other side of the board (pill side). If you de-solder and pull out the driver, you will see the attiny13a on the other side.
This thread explains everything - Guide: how to flash ATtiny13a based drivers (NANJG, QLITE, etc.) with custom firmware