First of all be sure to have the control the burglar alarm system.
If you are the first user you need to save the PIN code in Home + Security app.
If another member of the house already associated the burglar alarm system, you need to get the control.
For more information check the tutorial: https://www.youtube.com/watch?v=_qEkuebND6U&list=PLlaDNT-XSIbcAbndD7ENMUMoSZXDKOm0o&index=5
check if all devices are correctly connected to the network or contact your installer.