Increasing client_max_body_size in Nginx conf on AWS Elastic Beanstalk

I'm running into **"413 Request Entity Too Large"** errors when posting files larger than 10MB to our API running on AWS Elastic Beanstalk. I've done quite a bit of research and believe that I need to up the **client_max_body_size** for Nginx, however I cannot seem to find any documentation on how to do this using Elastic Beanstalk. My guess is that it needs to be modified using an ebetension file. Anyone have thoughts on how I can up the limit? 10MB is pretty weak, there has to be a way to up this manually.