Required Gallery images

Hi,
you can do that either with the Custom Fields extension (https://wpadverts.com/extensions/custom-fields/) or using the Forms API.

With the Forms API, you can add the code below in your theme functions.php file or even better create a new blank plugin (https://wpadverts.com/blog/how-to-use-code-snippets-in-wordpress/) and paste the code there, it will require users to upload at least one file to the gallery

add_filter( "adverts_form_load", "limit_file_uploads" );
function limit_file_uploads( $form ) {
    if( $form['name'] != "advert" ) {
        return $form;
    }
    foreach( $form["field"] as $key => $field ) {
        if( $field["name"] != "gallery" ) {
            continue;
        }

        $form["field"][$key]["validator"] = array();
        $form["field"][$key]["validator"][] = array(
            "name" => "upload_limit",
            "params" => array( 
                "min" => 1,     // minimum files to upload
                "max" => 20     // maximum file uploads
            )
        );
        break;
    }
    return $form;
}

Thanks again Greg.