"code":"Authorization_RequestDenied","message":"Insufficient privileges to complete the operation."

Hi All,

I am trying to hit the Graph API EndPoint but its giving me below error. Do you think anything is missing. I tried it from Postman. First call is to fetch the token and second call to fetch user details

{

    "error": {

        "code": "Authorization_RequestDenied",

        "message": "Insufficient privileges to complete the operation.",

        "innerError": {

            "date": "2021-09-02T04:10:16",

            "request-id": "4e9482f0-6148-4097-9fe6-a1587f8ebf3f",

            "client-request-id": "4e9482f0-6148-4097-9fe6-a1587f8ebf3f"

        }

    }

}

EndPoint to fetch user - https://graph.microsoft.com/v1.0/users/firstname.lastname@myCompany.com