Since you haven’t shared your script, I don’t know if this approach will work for you, but this is how I use alerts with scripted logic. Instead of using a REST notifier, I use a notify group with an empty set as the value of services. Alerts can be targeted at that notifier, and an automation can be triggered off the service call event created by the alert.
notify:
- platform: group
name: scripted_alerts
services: []
alert:
whirlpool_temperatur:
name: Die Temperatur des Whirlpools ist unter 6 Grad
entity_id: input_boolean.ztest_new_bool
state: "on"
skip_first: true
repeat:
- 1
- 2
- 3
notifiers:
- scripted_alerts
message: "Achtung: Die Temperatur des Whirlpools ist unter 6 Grad"
title: "Temperatur des Whirlpools"
data:
type: "tts"
duration: 6.3
automation:
- id: scripted_alerts_00001
alias: Scripted Alerts
description: Play message from "scripted_alerts"
trigger:
- platform: event
event_type: call_service
event_data:
domain: notify
service: scripted_alerts
variables:
data: "{{trigger.event.data.service_data.data | to_json}}"
condition: []
action:
- service: script.sprachausgabe
data:
message: "{{trigger.event.data.service_data.message}}"
title: "{{trigger.event.data.service_data.title}}"
type: "{{data.type}}"
duration: "{{data.type}}"
EDIT: Modified action to reflect OP’s script call.