If you have the Chrome browser on Windows 10, Mac, Linux, Chromebook, or Android, you can now flash Device OS (including bootloader and soft device) and the cloud debug firmware right from your browser with no additional software install required.
You can also view the results right from the web page, and there are buttons to copy the log to the clipboard or download it as a file, too.
https://docs.particle.io/cloud-debug/
If you want to learn more about the cloud debug firmware, want to install it manually, or don’t have Chrome, there is more information here.