Template Trigger Sensor

I’ve read the documentation at Template - Home Assistant and various threads in this forum but am struggling to get this working.
In my config.yaml I have “template: !include template.yaml”
In the template.yaml I have some working template sensors but I cannot translate the example in the documentaion into my file.

#EMS-ESP Working Hours
sensor:
  - name: 'System Uptime (hr)'
    unit_of_measurement: 'hr'
    icon: 'mdi:clock-check-outline'
    state: >
      {% set mins = states('sensor.system_uptime_sec') %}
      {% set hours = ((mins | int /  3600) | string).split('.')[0] %}
      {{hours}}  
	  
# Total Electricity Yesterday
trigger:
  - platform: time_pattern
    hours: 23
    minutes: 59
   sensor:
    - name: 'Smart Meter Electricity Energy Yesterday'
      unit_of_measurement: "kWh"
      state: {{states('sensor.smart_meter_electricity_import_today_new')|float(3)}}
#EMS-ESP Working Hours
- sensor:
    - name: 'System Uptime (hr)'
      unit_of_measurement: 'hr'
      icon: 'mdi:clock-check-outline'
      state: >
        {% set mins = states('sensor.system_uptime_sec') %}
        {% set hours = ((mins | int /  3600) | string).split('.')[0] %}
        {{hours}}  
	  
# Total Electricity Yesterday
- trigger:
    - platform: time_pattern
      hours: 23
      minutes: 59
  sensor:
    - name: 'Smart Meter Electricity Energy Yesterday'
      unit_of_measurement: "kWh"
      state: {{states('sensor.smart_meter_electricity_import_today_new')|float(3)}}

Template wants an array of items. For each item you can define a trigger and then sensors, binary sensors, selects, etc. that have their state set from that trigger. Or omit trigger for a item if you just want a bunch of sensors, binary sensors, selects, etc. that are set whenever anything in their template changes.

Thanks. I can see I missed the very first hyphen before ‘sensor:’
I actually had 17 sensors with templates that I had moved from sensor.yaml and it passed all checks and was running perfectly until I tried to add to add the ‘trigger’.
I will add in the hyphen and re-indent everything. Once it works I have a bunch of midnight events in automations that will be joining my ‘electricity yesterday’ .