Get authorization info of Azure AppService authorization by PHP
Advanced usage of authentication and authorization in Azure App Service
https://docs.microsoft.com/en-us/azure/app-service/app-service-authentication-how-to
-> Azure App Service passes user claims to your application by using special headers.
X-MS-CLIENT-PRINCIPAL-NAME
X-MS-CLIENT-PRINCIPAL-ID
X-MS-TOKEN-AAD-ID-TOKEN
X-MS-TOKEN-AAD-ACCESS-TOKEN
X-MS-TOKEN-AAD-EXPIRES-ON
X-MS-TOKEN-AAD-REFRESH-TOKEN, etc.
This is a sample code to get these values by PHP.
Authentication and authorization in Azure App Service and Azure Functions
https://docs.microsoft.com/en-us/azure/app-service/overview-authentication-authorization
-> FYI, "_SERVER['REMOTE_USER']" is currently null.