Power consumption , add consumtion

Configuration
1

Hi ! I use this code to show power consumption of smart socket.

   -platform: integration
    source: sensor.sonoff_10012c4900_power
    name: "Radiator energy"
    unit_prefix: k
    round: 2
    method: left

All ok, but I would like to add the consumption of the previous days (37,74kWh), before using the home assistant.

I try with

   -platform: integration
    source: sensor.sonoff_10012c4900_power
    name: "Radiator energy"
    unit_prefix: k
    round: 2
    method: left
   value_template: "{{((value | float) + 38.74) | float}}"

but not work, i get errror

Invalid config for [sensor.integration]: [value_template] is an invalid option for [sensor.integration]. Check: sensor.integration->value_template. (See ?, line ?).

Thankyou for help