Physical reset button: Hold the button down on the raspberry pi pico while plugging it in. There is no reset button on the pcb.
Keycode in layout: Press the key mapped to QK_BOOT if it is available

Make example for this keyboard (after setting up your build environment):

make crowboard:default

Flashing example for this keyboard:

make crowboard:default:flash

See the build environment setup and the make instructions for more information. Brand new to QMK? Start with our Complete Newbs Guide.