Problem with this automation

alias: "Geekroom: warning"
description: ""
use_blueprint:
  path: myGithub-Markus/flashing_lights.yaml
  input:
    activated: automation.hallway_downstairs_frontdoor_sensor
    light_target:
      device_id:
        - c8f79b53cf58c6387f422c50ed1e5bc4
        - 861fbade54c7fc521dc3c0eac41c68ca
    activated_timeout: 8
    delay: 800