Yes, this is easy via the app. There are 3 options for the siren.
Download and open the App |
|
Go to Settings |  |
Go to Siren (Settings) |  |
1. Choose 'Loud' and confirm with 'Ok' |  |
2. Choose 'Low' and confirm with 'Ok' |  |
3. Choose 'Mute' and confirm with 'Ok' |  |
The notification via the mobile network does not depend on the volume of the siren.