Add 2 mqtt values into one Wh value

Configuration
1

I’m trying to ADD 2 values into one ( 100 + 100 = 200). How do I do that? This does not work: value_template: ‘{{ value_json.CIH + value_json.CIL }}’

    - name: 'Remi Import Elektriciteit woning H+L Wh'
      unique_id: remi_mqtt_ch0_import_hl
      state_topic: '244cab254dfc/PUB/CH0'
      value_template: '{{ value_json.CIH + value_json.CIL }}'
      unit_of_measurement: 'Wh'
      device_class: energy
      state_class: measurement
      json_attributes_topic: '244cab254dfc/PUB/CH0'
      json_attributes_template: '{{ value_json | tojson }}'
2

Post an example of the payload that’s published to 244cab254dfc/PUB/CH0.