(1) Open the Calibre application (https://calibre-ebook.com/) on your computer.
(2) While in Calibre application on your computer, select "Connect/Share", and then click "Start content server".
(3) Keep the Calibre application mentioned in step (2) opened on your computer and keep the content server mentioned in step (2) connected as well, open Aldiko on your iOS device, click "My Catalogs".
(4) While in My Catalogs section in Aldiko, click "Add" at the top right corner and then select "Calibre". After that, Aldiko will try to connect to your Calibre server and look for book catalogs in your Calibre server. This may take a while. When the search is done. All found book catalogs in your Calibre server will be displayed.
(5) You can select the book catalogs found in step (4) and download books from the book catalogs.
(6) After you finish downloading all the books you need from the book catalogs, you can stop content server in Calibre application and quit Calibre application on your computer .