human
write me a python function formatted with markdown to authenticate with the ebay rest api using client id and secret retrieved from environment variables and return the access token. be sure to validate the status code is 200, and throw an exception if it is not
gpt
--- Reasoning ---
1. Is the question multiple-choice question?
No
2. Is it implied multiple-choice question?
No
3. If two experts were independently asked the question, will the final answer be exactly the same?
No

--- Answer ---
open