Default value of fields

Hello,

Why doesn’t this script use the default values when running this script directly ?

alias: Stuur notificatie
description: Sturen van een notificatie
fields:
  titel:
    name: Titel
    description: Titel van het bericht
    selector:
      text:
    default: Check brievenbus !
  boodschap:
    name: Boodschap
    description: De boodschap van het bericht
    selector:
      text:
    default: Postbode kwam langs
sequence:
  - service: notify.notification_devices
    data:
      title: "{{ titel }}"
      message: "{{ boodschap }}"
  - service: notify.gmail
    data:
      title: "{{ titel }}"
      message: "{{ boodschap }}"
mode: single

I tried something like this, but this doesn’t work :

  - service: notify.notification_devices
    data:
      title: >
        {% if titel | length | int > 0 %}
           "{{ titel }}"
        {% else %}
           "No title"
        {% endif %}