There might be the situations that you may need to add banner, buttons etc. at detail or popup page.
Flexi has many features but it can never achieve all the user requirements but there are many plugins at wordpress respiratory which has shortcode option to execute.

Let’s begin with live example and steps completed

Note: This will not display the inserted code. Since we are inserting into detail page. We must know which layout the detail page is using. It can be basic or complex layout. We can determine it at Flexi -> ‘All Post’ page. If it shows ‘detail layout’ as ‘Default’. Check which layout is specified as default at Flexi -> Setting -> Detail tab -> ‘Select Detail Layout’ field
In our case it is ‘basic layout’, hence we need to go Flexi ->Setting -> Detail tab -> ‘Basic – Layout’ section.
../wp-admin/admin.php?page=flexi_settings&tab=detail&section=flexi_detail_layout_basic