Sending an image from a previous response in an email

Configuration
1

I have an action triggered by motion from my cameras that is using llmvision to send me an email with an AI description of the scene. This also saves an image and returns a path to it such as “/config/www/llmvision/4598a4ca-0.jpg”.

I then have an action configured to send the email, but the image is not being included. So far I have:

  - action: notify.username_gmail_com
    metadata: {}
    data:
      title: Driveway Motion
      message: '{{ response.response_text }}'
      target: [email protected]
      data:
        images:
          - ' {{ response.key_frame }}'

Where response.key_frame is the path to the image in /config/www. But no attachment is included. Any idea why this might be and what I need to fix?