Asking for a customised app that alarms me by a network event

Hi I wonder if developers here can help me to build this feature.

What I want is to let the watch vibrate when a network event takes place, in my case, I have an openwrt router that can be configured to execute a script when a specific Mac address is connected to the local wifi, and I wish to receive it on my Garmin Fenix 6 Sapphire

My understanding is that the watch doesn't have any network capability and relies entirely on Bluetooth, hence the mobile phone must be online and nearby for this kind of thing to work, right?

A typical use-case is to get an alarm to stop doing whatever things your parent does not allow you to do before they get back home and open the door, or for a restaurant manager to know the owner of the restaurant is here and come out to welcome him. Apparently this can be spoofed, but that is not my concern.