Install Chromium from the Snap Store.
Click Permissions, then enable Access USB hardware directly.
Run in a terminal:
sudo sh -c 'echo "SUBSYSTEM==\"usb\", ATTR{idVendor}==\"0a5c\", MODE=\"0666\", GROUP=\"plugdev\"" > /etc/udev/rules.d/71-homey.rules'
This will give Chromium access to Homey Pro as USB device.
Reboot, then follow the instructions.
The above instructions might also work for you.