rp2040 firmware for using yubideck io
1.Install Arduino IDE
2.Install Arduino-Pico core follow instructions in https://arduino-pico.readthedocs.io/en/latest/install.html
3.Open Arduino IDE and select board:Raspberry Pi Pico in Tools -> Board
4.Select Adafruit_TinyUSB in Tools -> USBStack
5.Push and hold the BOOTSEL button on the Pico, then connect to your computer using a micro USB cable. Release BOOTSEL once the drive RPI-RP2 appears on your computer.
6.Select UF2 Board in Tools -> Port
7.Upload the code
should be similar on other MCUs that support TinyUSB