Check the note below (on how to create your own Desktop folder) taken from this documentation article
Some Linux distributions like Ubuntu will use localized paths (for example, the Desktop folder is renamed with the related word used in the locale language). That might cause for step 3 to fail due to a missing folder named Desktop with an error message of type Could not find a part of the path .... Until an out-of-the-box solution is implemented, you could easily workaround this issue by creating a folder called Desktop at your root directory (
mkdir ~/Desktop) and then export the certificate to the newly-created directory. Once the certificate is installed, you could safely remove the directory.
I finally got fiddler everywhere to run and logged in successfully. My problem is I cannot export root certificate to desktop. I am on a chromebook using linux beta and there is no access to the desktop. I only have access to the downloads folder. If there was an option to choose where to export the certificate that would help.