How can I start a NPM app from a desktop shortcut?

I have created a desktop shortcut for a npm application called TMXEditor, but it doesn't work. I can launch the app if I do cd /home/souto/Apps/maxprograms/TMXEditor && npm start on a terminal. I put that in a bash file /home/souto/Apps/maxprograms/TMXEditor/start.sh. The application runs if I just run that script in a terminal. Its exact contents are:

#!/bin/bash
cd /home/souto/Apps/maxprograms/TMXEditor && npm start

So I have created the .desktop file pointing to that:

[Desktop Entry]
Name=TMXEditor
Exec=/home/souto/Apps/maxprograms/TMXEditor/start.sh
Icon=/home/souto/Apps/maxprograms/TMXEditor/icons/tmxeditor.png
StartupNotify=true
Terminal=false
Type=Application
Categories=Translation;
Comment=
Path=/home/souto/Apps/maxprograms/TMXEditor

The .desktop file is saved as /home/souto/.local/share/applications/TMXEditor.desktop. I can see the shortcut in Rofi, but when I run it from there the application will not start. I have also tried putting Exec=xfce4-terminal -e "/home/souto/Apps/maxprograms/TMXEditor/start.sh. In that case, I can see a terminal blinking for a fraction of a second but still the application will not run. Both the .desktop and the bash files are executable:

-rwxrwxr-x 1 souto souto 296 feb 19 14:27 /home/souto/.local/share/applications/TMXEditor.desktop
-rwxrwxrwx 1 souto souto 67 feb 19 13:53 /home/souto/Apps/maxprograms/TMXEditor/start.sh

My desktop environment is Xfce 4.18 (on arch linux) and I normally use zsh 5.9 as the shell. I'd appreciate some help to debug this shorcut. Thanks.