@AlexWhi 

Hi,
Currently, the notification schedule applies to the detection and doorbell video call. If you want to be notified when the camera detects people at night and the doorbell video call notification won't be affected, please try the following steps.
1. On the doorbell camera's Notification page, enable the Activity Notifications, select none on the Activity Type, and set the Schedule to Always.

2. Go to the Tapo app > Smart >Automation, and add an automation entry: How to create Smart Action (Automation or Shortcut) on the Tapo app
1) Effective Time > Custom Time > Set the time you want to receive notification.
2) When doorbell camera detects people, then Send Me Notifications.
 

Best Regards