Extracted from the previous post link
Get alerts at a certain time or when No one at Home
You can customize notifications for your HomeKit or Matter accessories to alert you at specific times and based on who's present in your home.
- Open the Home app.
- On an iPhone or iPad, tap an accessory. On a Mac, click an accessory.
- Scroll down and select Status and Notifications. Turn on Activity Notifications, then choose from these options.
- Time: Set a time that you want to get alerts for your accessory.
- People: Get alerts for the accessory when you or someone arrives or leaves your house. If you choose this option, you need to set up a home hub and make sure that everyone who can control your home has My Location set to their primary iPhone or iPad and Share My Location turned on in Settings > [your name] > Find My.
- Tap or click Back
in the upper-left corner, then Done.
To see notifications that you set up in the Home app on more than one device, you need to set up notifications on each device.
Not all smart home accessories support notifications.