我相信您会收到此错误，因为您传递的用户名/密码无权访问Power BI.请确保将PowerBI凭据(帐户用户名和密码)传递到REST API端点.

I believe you are getting this error as the username/password which you are passing does not have access to Power BI. Please make sure that you are passing the PowerBI Credentials (Account User Name and Password) to REST API end point.