Following things need to be installed:

1. flask: the framework to to the backend
2. flask_cors: to handle the cross-origin-exception Prerequisite
3. pip install flask
4. pip install flask-cors
5. pip install geopandas
6. pip install xlrd
7. pip install Rtree

To stop running at port :5000 run following:

1. sudo lsof -i:5000
2. kill -9 xxxx

The project is run by the following command: FLASK_APP=starter.py flask run

The file path looks as follows:

1. starter.py
2. index.html
3. static/ 3.1 css/ style.css 3.2 js/ mapscript.js 3.3 libraries/ leaflet/ jquery.min.js