How to configure parameters (maximum file size and timeout) in an elastic beanstalk machines ?

We are not able to configure "nginx" in an elastic beanstalk machine. Our need is to change the maximum file size and timeout parameters. We managed to change these parameters (maximum file size and timeout) in "nginx" when the system is configured to create a server from a repository but, when we try to do the same in a docker image, these parameters are not changed. Can anyone help us ?