slipstream | NAT Slipstreaming allows an attacker to remotely access | TCP library

I am following this tutorial for encrypting and decrypting data with the Python cryptography package and this other SO Post is very similar but doesn't include sending the data over the internet to an http server which I am curious to figure out how. The tutorials are about using Fernet key as the encrypting method.

So this code below is reading a CSV file of time series data, and the encrypting part works just fine its just how can I package this as form data? Pandas read CSV, to json, and then I think to bytes of data for encrypting, is that possible to package as form and POST it to an HTTP Python Flask app endpoint?

This code runs fine below until it hits the requests.post part to POST the encrypted data:

There's an API that I am experimenting with that outputs XML.

Could anyone tell me if I have something wrong my code to parse the API response or is it a problem with the API itself?

I can use a put command with this: