Twilio Error – 11200 HTTPS Retrieval / Python Flask Application

Solution

@app.route("/twilio", methods=["POST"])
def inbound_sms():
    response = MessagingResponse()
    inbound_message = request.form.get("Body")
    if inbound_message == "Hello":
        response.message("Hello back to you!")
    else:
        response.message("Hi! Not quite sure what you meant, but okay.")
    return Response(str(response), mimetype="application/xml"), 200

$ http --form POST http://127.0.0.1:5000/twilio Body=Hello
HTTP/1.0 200 OK
Content-Length: 96
Content-Type: application/xml; charset=utf-8
Date: Fri, 26 Feb 2021 12:15:30 GMT
Server: Werkzeug/1.0.1 Python/3.6.9

Hello back to you!