你好，

您是否按照https://developer.microsoft.com/zh-CN/graph/docs/concepts/auth_v2_service中的步骤进行操作?
您必须将新应用注册到您的租户，并首先获得管理员的同意，并要求租户中的/adminconsent.获得同意后，您可以调用TokenRequest帖子来获取令牌.

Did you follow the steps in https://developer.microsoft.com/en-us/graph/docs/concepts/auth_v2_service ?
You must register the new app to your tenant, and obtain Administrator consent first with request to /adminconsent in the tenant. Once you have the consent, you can invoke TokenRequest post to get the token.

简而言之，您可能会错过本文的第1-3步.

In short you might miss the step 1-3 from the article.