qmk new-keymap -kb crkbd/rev1 -km <keymap_name>
qmk compile -kb crkbd/rev1 -km <keymap_name> -e CONVERT_TO=promicro_rp2040
This creates the uf2 file to flash the keyboard.
Press the reset button on the keyboard 2 times.
Drag & drop the uf2 file to the newly connected device.