To access it you have to navigate to the PixiePanel/ Gallery/ Gallery Settings.
Admin Panel → PixiePanel → Gallery → Gallery Settings
This is where you change the gallery background for the gallery. To change it, simply click CHOOSE BACKGROUND and upload an image to your media library & save it. Recommended image size: 1920x400 pixels.
Note: If left blank, the default image will be displayed.
Gallery Content Settings
This is where you add the content, found in the intro section of the gallery. For it to be fully displayed like the demo/preview, you need to fill up all of the fields. Which are the following:
Gallery Title - The topline text a.k.a header text.
Heading - The bottom line text or the subtitle.
Description - A small description of what you’re going to display in your gallery.