How do i work with API testing on default nginx home page?

I have setup nginx with docker and now i would like to host a simple page which can process POST and GET responses. Basically, i would like try python API testing using python in that page.

I have a default nginx page which process POST requests. So, i was able to test that. But, i'm confused on how to POST data on that page.

Existing code to test GET calls using requests library

r = requests.get(url,headers=headers)
    assert r.status_code == 200