Flask How to send back JSON response

from flask import Flask,jsonify,request

  app =   Flask(__name__)

  

@app.route('/returnjson', methods = ['GET'])

def ReturnJSON():

    if(request.method == 'GET'):

        data = {

            "Modules" : 15,

            "Subject" : "Data Structures and Algorithms",

        }

  

        return jsonify(data)

  

if __name__=='__main__':

    app.run(debug=True) 

references:

https://www.geeksforgeeks.org/how-to-return-a-json-response-form-a-flask-api/