Keyword HTTP trigger returning 400

Hi!

I have a keyword that is triggering an HTTP request to my flask app. However, it's constantly returning 400.

payload = request.json
phone_number = payload.get('phone_number')

This is how I'm parsing the payload, which may be the issue. Any ideas of where I'm going wrong?

My request is configured as so on postscript:

Content Type

application/json

Method
POST

Body

keyword BONSAIBUDDY
phone_number e.g. 12345678910
shopify_customer_id e.g. 1
postscript_subscriber_id e.g. 1
triggered_at e.g. 2018-01-01 12:00:00.000000