Once you opened the project, you need to edit a variable value to point the app to the right url of the web application.
For iOS app, please browse to www/js/btt/btt.js in the project , find the variable ServerAddress, then set its value to the right url of the web application context root, then save the modification.
For Android app, please browse to the “assets/www/js/btt/btt.js” in the project, find the same variable ServerAddress and set its value to the right web application context root in your environment.