I have downloaded this plugin, but I cannot find any advice on how to operate it. I have opened a page (which I have created) rendering part of a high res iiif image, whose whole iiif pyramid is available for viewing. But I cannot find any button that activates the plugin. The plugin promises "With this addon installed, you will be able to download the highest available resolution for files available on digital libraries compatible with the IIIF protocol." How can I download the whole high res image?