"Invalid api key or secret" error in Server-to-Server OAuth app

[elisa.zoom (Elisa)]

No, Its quite interesting to me cause I have not been able to replicate this issue on my end.
I wrote this guide about a month ago, maybe it can help you troubleshoot the error:

How to user Server-to-Sever OAuth app with Postman

How to use our Server-to-Server OAuth with Postman? As some of you might be aware of, our JWT app is being deprecated by June 2023 and we encourage you to migrate to the newly introduced Server-to-Server OAuth App That being said, here is a quick and simple guide on how to use or new app with Postman As stated in our documentation here: This new app type facilitates OAuth-authenticated requests between servers without end-user involvement. And this grant type enable your private server a…

Let me know if it helps!
Best,
Elisa