Within the PDF Catalog configuration page, you can setup a 'Block' on your front office to make your PDF catalog available for download by visitors on your shop.
First open the block options page
Once you have selected the location of the block and entered a name, right click on the catalog you need to add > Copy link address
In the block content, right click to 'Insert link'
For more information on the PDF Catalog Module, please refer to our online documentation.