On the first run on Xubuntu 16.04 insync suggested to install Thunar extensions, but it opened a terminal where asked for a password via sudo, but my user is not in sudoers and cannot execute commands via sudo.
And I want to see, what will be done after entering the password. You can you bash -x to execute the script. And please do not put files not using the packaging system while you have deb/rpm packages of file managers extensions