Receiving Werkzeug. exception. Bad Request error when using GET with an endpoint

[robogeek]

Hello,

I was trying to implement an API using Python, and flask to help myself learn and practice REST.

The idea was to receive a HTTP POST with data that looks like as such:
{"startDate":"2015-07-01","endDate":2015-07-08","within":{"value":9000,"units":miles}}

I was able to create a POST method , and I am able to receive the data (both in POSTMAN and in the browser). Here is the relevant code :

@neows.route('/UserInput',methods=['GET','POST'])
def UserInput():
        startDate = request.args.get('startDate')
        endDate = request.args.get('endDate')
        #print (type(startDate))
        #print (type(endDate))
        getAsteroids(startDate,endDate)
        return jsonify(request.args)

But when I use the data provided above to GET some data from a NASA API I am receiving this error: werkzeug.exceptions.BadRequestKeyError

Here is the url I am trying to hit : Nasa Endpoint

I am able to hit the url both on POSTMAN and browser, outside of my code.

Here is the relevant piece of code

def getAsteroids(startDate,endDate):
        API_KEY='8Yrp7t6VDsh5DahF7i1hzLEykr9IHljF8LrZ70RL'
        print (startDate)
        print (endDate)
        [color=#C0392B]result=request.args["https://api.nasa.gov/neo/rest/v1/feed? 
        start_date="+startDate+"&end_date="+endDate+"&api_key="+API_KEY+""][/color]
        	

The line above in red is throwing the error. I would really appreciate if someone could help me understand and resolve the issue.

Thank you