In order to flash the board using WebUSB on Linux, udev rules will need to be configured. Without doing this you will get an "Access denied" error.
- Create a file named
/etc/udev/rules.d/60-rp2040.rules
as root or with sudo, which contains the following:
SUBSYSTEMS=="usb", ATTRS{idVendor}=="2e8a", MODE:="0666"
- Run
sudo udevadm trigger
- Run
sudo udevadm control --reload-rules
- If the board was plug in previously, unplug and plug it back in.