Open your terminal and navigate to the project folder ( API version directory or Firebase version directory ) and install NodeJS dependencies :
** $ npm install **
Once all the node dependencies installed successfully you can run the app in the browser window with :
** $ ionic serve **
You can also run this app with Ionic Lab , It will open apps in multiple device at a time and it's good way to Test your own apps .
**$ ionic serve --lab **
If there any issue please google it or if you didn't find any solution report us , we will looked into it.