GD Knowledge Base Pro has a lot of shortcodes included, and each one has many parameters that can be very tough to setup. Because of that, the plugin supports the use of Shortcodes Shortcake UI plugin for shortcodes visual editing.
Once you activate Shortcake plugin, it will add the new button into the TinyMCE editor called Add Post Element next to Add Media button. When you click on Add Post Element, you will see the list of available shortcodes:
When you click on the shortcode you want, you will get to edit the shortcode before inserting it into the editor. When added to the editor, the shortcode will be displayed as a block, and you can edit it again if you need. If you switch the editor to Text view, you will see the shortcode as it is.