Error running mycroft-gui

Hello,

I got mycroft-gui from: GitHub - MycroftAI/mycroft-gui: The Graphical User Interface used by the Mycroft Mark II and more

Running on my ubuntu machine: start_gui_and_mycroft.sh
getting below error:
Launching GUI
./start_gui_and_mycroft.sh: line 35: mycroft-gui-app: command not found
I searched but can not find mycroft-gui-app. Where should I get mycroft-gui-app script?

Thanks a lot!

Run ./dev_setup.sh in mycroft-gui folder to set it up first.