我要怎麽用graph api訂閱resources裡的rooms

當我在 https://admin.microsoft.com/Adminportal/Home#/ResourceMailbox 新增一個 room 的時候我無法使用 graph api 訂閱這個 room

[POST] https://graph.microsoft.com/v1.0/subscriptions

{
	"changeType": "created,updated,deleted",
	"notificationUrl"
	"resource": "users('{room_email}')/events",
	"expirationDateTime"
	"clientState": "secretClientValue"
}

但是我會得到回應

{
 "error": {
	"code": "ExtensionError", 
	"message": "Operation: Create; Exception: [Status Code: BadRequest; Reason: The value 'https://outlook.office365.com/api/v2.0/Users('room_email')/Events' of parameter 'Resource' is invalid.]", 
	"innerError": {
		"date": "...", 
		"request-id": "...", 
		"client-request-id": "..."
}}}

如果我要訂閱 resource 裡的 room 我的payload有錯誤嗎？

或是 room 是無法訂閱的？