@CarlosMartins podes criar uma automation deste estilo:
automation:
- alias: 'Enviar SMS Alarm Triggered'
trigger:
- platform: state
entity_id: alarm_control_panel.ha_alarm
to: 'triggered'
action:
- service: joaoapps_join.sthope_send_sms
data:
message: "ALARM! The alarm has been triggered"
number: "Numero para enviar"