Repeat.index variable

how to write this script to update the sensors sensor.test1, sensortest2, sensortest3 etc. etc.

update:
  mode: restart
  sequence:
    - alias: "update sensor"
      repeat:
        count: '10'
        sequence:
          - service: homeassistant.update_entity
            data_template:
              entity_id: >-
                sensor.test{{ repeat.index }}