Adding 'custom:hui-element' to SVG 'ha-floorplan'

Configuration Frontend
1

Dear Coders,

I’m using SVG image with ExperienceLovelace ‘ha-floorplan’. I would like to add ‘custom:hui-element’ cards to it, but it doesn’t work. My code:

views:
  - title: Love-02
    path: floorplan
    theme: theme-3dsmax
    type: panel
    cards:
      - type: custom:floorplan-card
        config:  
          image: '/local/images/floorplan_optimized.svg'
          stylesheet: '/local/floorplan.css'
          console_log_level: error
          log_level: info
          rules:
            - entities:
                - switch.light_01
                - switch.light_02
              tap_action: false
              state_action:
                action: call-service
                service: floorplan.class_set
                service_data: 'light-${entity.state}'
            - entities:
                - switch.light_01
                - switch.light_02
              tap_action:
                action: 'toggle'
              state_action:
                action: call-service
                service: floorplan.style_set
                service_data:
                  element: "${entity.entity_id.replace('switch.', 'light_overlay.')}"
                  style: |
                    >
                    if( entity.state !== "on" ) return "display: none;";
                    return `
                      display: block;
                      filter:
                        brightness( calc( ${entity.attributes.brightness}/255 ) );

            # Would like to add this 'markdown' content
            - type: custom:hui-element
              card_type: markdown
              content: "This is the content."
              style:
                left: 50%
                top: 50%
                width: 300px

Could you help me, please?

Thank you in advance.