Hello Hymced!
To get notifications you have to set this in the app Home from Apple and would need an Apple TV 4/4K or HomePod to receive it even when remote.
The 100 dB alarm on the accessory will start once a leak is detected, This can't be disabled. The notifications you get on the iOS accessory is a HomeKit based notification and this can be disabled.
Best, volker
Oct 10, 2020