403 Error production server from client, same auth and payload work from postman

I'm at a loss on this. I'm fairly new to a code base where the previously developer left. We have an integration with zillow where they post leads to our system.

The uri looks like this. https://www.ourcompany.com/api/leads?authorization=randomstuff

Standard JSON sent in body.

From Postman, I get a 200 everytime. I cannot get it to fail. From their system, they get a 403 error. They can also post it manually, but from their system it fails.

Unfortunately, I'm not much of a dev ops guy and don't really know what I am doing or where to look. I don't see anything in the nginx log files or laravel log files other than postman. The IP address for zillow is not banned on our server.

Laravel 5 on nginx/1.4.6 (Ubuntu). We are going through cloudflare which I think is potentially where its getting tripped up, but we don't have the cloudflare account at this time.

So, any ideas besides cloudflare, or is that most likely the source of the problem?

via Chebli Mohamed