I think this is all you will need - the camera component to load the particular IDR. I believe it will work even withouty importing the BOM platform.
camera:
platform: generic
still_image_url: http://www.bom.gov.au/radar/IDR643.gif?{{ now().strftime("%Y%m%d%H%M") }}00
name: RainRadar
limit_refetch_to_url_change: true