Temperature sensor text_template not writing text over svg but only showing status when clicked

[lionberger]

I am trying to display the temperature as a dynamic text label on the floorplan’s svg file but all I achieved at the moment is to be able to show the temperature when the svg entity with the matching id is clicked (see below):

I currently use in my configuration.yaml:

sensor:
  - platform: mqtt
    name: "Temperature"
    state_topic: "temperature/sensor1"
    unit_of_measurement: '°C'
    value_template: "{{ value }}"

and in ui-lovelace.yaml

cards:
          - title: Ground Floor
            type: 'custom:floorplan-card'
            config:
              image: /local/floorplan/examples/simple/simple.svg?v=1.1.14
              stylesheet: /local/floorplan/examples/simple/simple.css?v=1.1.14
              log_level: error
              debug: true
              rules:
                - entity: sensor.temperature
                  element: temp.text
                  text_template: '${sensor.temperature}'

what I’d like is for temperature to be shown as text as in the screenshot below.