Improve error handling with OpenAI

First of all, this is a very exciting project. Thank you for sharing.

I'm running into this issue when I try my first screenshot conversion:

ERROR: Exception in ASGI application

ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: certificate is not yet valid (_ssl.c:1007)

(There are many error lines but I believe these are the most important)

Edit: this could be an issue with openai itself

https://status.openai.com/