IM通知
```
{
"appoint": {
"appoint_id": "",
"meet_id": "",
"room_id": "",
"password": "",
"title": "",
"intro": "",
"start_time": "0001-01-01T00:00:00Z",
"end_time": "0001-01-01T00:00:00Z",
"state": "",
"owner": {
"user_id": "",
"nickname": "",
"avatar": ""
},
"repeat": null,
"remind_times": null,
"invite_users": null,
"last_record": {
"meet_id": "",
"room_id": "",
"title": "",
"start_time": "0001-01-01T00:00:00Z",
"mute_all": "",
"record": "",
"lock_meeting": "",
"internal": "",
"screen_share": "",
"state": "",
"owner": {
"user_id": "",
"nickname": "",
"avatar": ""
},
"holder": {
"user_id": "",
"nickname": "",
"avatar": ""
}
}
},
"invite_state": ""
}
```