curl --request GET \
  --url https://ywe3crmpll.execute-api.us-east-2.amazonaws.com/stage/invoices/qb-classes \
  --header 'x-api-key: <api-key>'

import requests

url = "https://ywe3crmpll.execute-api.us-east-2.amazonaws.com/stage/invoices/qb-classes"

headers = {"x-api-key": "<api-key>"}

response = requests.get(url, headers=headers)

print(response.text)

const options = {method: 'GET', headers: {'x-api-key': '<api-key>'}};

fetch('https://ywe3crmpll.execute-api.us-east-2.amazonaws.com/stage/invoices/qb-classes', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "message": "Unauthorized"
}

{
  "message": "Request URL not found"
}

{
  "message": "Internal Server Error"
}