Hi @whiteboardtutor
Thanks for reaching out to the Zoom Developer Forum and welcome to our community, I am happy to help here!
I understand that you are having issues when trying to create a Server-to-Server OAuth app, this issue might be due to the settings in your account.
Here is a guide I wrote on how to use the Server-to-Server OAuth app and how to use it with Postman:
You can also look into this thread:
Best,
Elisa