Requests gets no out put and no error

[buran]

If that is all your code, you just define the get_request() function but never call it. Note that lines#9 and 12 are indented and are in fact part of function itself. Unindent lines#9 and 12 one level. The print should remain part of the function.

import requests
import json
import sys
 
 
def get_request(api_key):
    api_url='https://api.nasa.gov/planetary/apod'
    r= requests.get(api_url, headers = {"Content-Type": "application/json", "access_key": api_key})
    print(r.content)


api_key ='<my api key>'
get_request(api_key)

also if the response is json format, you can use r.json()