OAuth 2.0 Client Authentication. This article explains “OAuth 2.0 client… | by Takahiko Kawasaki | Medium
OAuth 2.0 Client Credentials: Client ID and Secret not urlencoded when using Basic Auth header · Issue #7138 · postmanlabs/postman-app-support · GitHub
The client credentials grant flow
OAuth 2.0 client credentials flow on the Microsoft identity platform - Microsoft Entra | Microsoft Learn