You can override ad detail page and do your necessary customization
Copy the following folder or specific files from this folder as you need
Source Folder and Files:
wp-content/plugins/classified-listing-pro/templates/
Destination Folder and Files:
Copy the folder or specific file to your theme or child theme
wp-content/themes/your-theme/classified-listing/
Files need to edit
Single Listing page template: single-rtcl_listing.php
Single Listing content: content-single-rtcl_listing.php
Single listing review: single-rtcl_listing-reviews.php