Unable to set a icon_template

Hi,

I try to make my icon_template works, it works in devtool template preview tab but when I put the code in configuration.yaml it throws an error

Invalid config for [sensor]: [icon_template] is an invalid option for [sensor]. Check: sensor->icon_template. (See /config/configuration.yaml, line 151).
I tried many things but do not figure out why it does not work.
I tried to set a variable to store sensor value to make it more readable but don’t knoww if we can set vars in icon_template.

I tried to format yaml with vscode yaml extension but the same.

mqtt:

  sensor:

    # **** MQTT Shelly Flood Battery ****

    - name: "MQTTT Shelly Flood Battery"

      state_topic: "shellies/shellyflood-987654321edcba/sensor/battery"

      unit_of_measurement: "%"

      device_class: battery

      icon_template: >

        {% if is_number(states('sensor.shelly_flood_987654321edcba_battery')) and states('sensor.shelly_flood_987654321edcba_battery') | float == 100 %}

            mdi:battery

        {% elif states('sensor.shelly_flood_987654321edcba_battery')|float <= 15 %}

            mdi:battery-outline

        {% else %}

            mdi:battery-{{(states('sensor.shelly_flood_987654321edcba_battery')|float / 10)|round*10}}

        {% endif %}

Device_class battery handles the icon and you don’t need the template.

Also, mqtt sensors don’t support an icon template, so you have to rely on the device class setting.

Ok, Thank you !