Can I design the Popup as I desire?

FireBox uses the new WordPress editor, Gutenberg, which allows you to create beautiful pages more easily and quickly by using a set of blocks that you can move and customize as desired.

There are numerous third-party plugins that offer additional blocks, providing you with endless possibilities for what you can create.

In addition to the Gutenberg editor, you can also use the Classic Editor, which allows you to populate content using shortcodes and HTML. However, please note that with the Classic Editor, you will not be able to customize campaign settings such as design, format, behavior, display conditions, actions, or PHP scripts, as these features require the Gutenberg editor. To make these changes, you can either enable the Gutenberg editor or exclude the "firebox" custom post type from using the Classic Editor.