“wpcargo_track_result_form” action hook is use to change the whole track result form template.

Copy and paste this sample code to change the track result template to the theme functions.php file.

// In this sample code the shipment information and the shipment history is removed.
add_action( 'wp', function(){
	global $wpcargo_track_form;
    function my_custom_wpcargo_track_result_form( ){
        // Get form submitted shipment number
        $shipment_number    = wpcargo_can_track_shipment( );
        // Check if the submitted shipment number found on the database
        $shipment_id        = wpcargo_trackform_shipment_number( $shipment_number );
        ?>
        <div id="wpcargo-result-wrapper">
            <div class="wpcargo-result wpcargo" id="wpcargo-result">
                <?php
                if ( !empty( $shipment_id ) ) :
                    $shipment 				= new stdClass;
                    $shipment->ID 			= (int)esc_html( $shipment_id );
                    $shipment->post_title 	= esc_html( get_the_title( $shipment_id ) );
                    ?>
                    <div id="wpcargo-result-print" class="wpcargo-wrap-details wpcargo-container">
                        <?php
                            do_action('wpcargo_before_track_details', $shipment );
                            do_action('wpcargo_track_header_details', $shipment );
                            do_action('wpcargo_track_after_header_details', $shipment );
                            do_action('wpcargo_track_shipper_details', $shipment );
                            do_action('wpcargo_after_package_details', $shipment );
                        ?>
                    </div>
                <?php else: ?>
                    <h3 style="color: red !important; text-align:center;margin-bottom:0;padding:12px;">No results found!</h3>
                <?php endif; ?>
            </div>
        </div>
        <?php
    }
    // Remove the default form template
    remove_action( 'wpcargo_track_result_form', array( $wpcargo_track_form, 'wpcargo_trackform_result_template' ), 10 );
    // Add new hook for the new form template
    add_action( 'wpcargo_track_result_form', 'my_custom_wpcargo_track_result_form' );

}, 25 );

Screenshot: