Desktop launch gnome-terminal -- command

I recently purchased the tx2 development kit, I state that I have not installed any kind of jetson pack, but I use the ubuntu 18.04.3 system as it arrived, I need to create a.desktop file in the desk that you throw me a file. sh which starts roslaunch. The problem is that if I run the command from terminal gnome-terminal - ./file.sh it works perfectly, but if I create the command in the desktop file with the syntax exec = gnome-terminal - ./file.sh the terminal starts but the .sh file does not start. The same file put in a pc with ubuntu 18.04 works very well. I don’t understand if the ubuntu 18.4 lts system of tx2 has problems with this type of file. I would not like to update the system. Can I update the jetson file without deleting all the programs already installed? Do I have to do it via another computer and then flash the jetson developer kit? Thanks Francesco.