You can’t use ChatGPT here, as it doesn’t have an API.
You can use HTTP + Groq method if you want free.
See the linked showcase I shared above for details.
Hope this helps! Let me know if there are any further questions or issues.
— @samliew
P.S.: Did you know, the concepts of about 70% of questions asked on this forum are already covered in the Make Academy. Investing some effort into it will save you lots of time and frustration using Make later!