wpcfe_shipment_after_tracking_number_header
“wpcfe_shipment_after_tracking_number_header” an action hook is use to add additional column in the shipment table header.
Copy and paste the following to for customized the label in the theme functions.php file
// Add additional header "Custom Data" add_action( 'wpcfe_shipment_after_tracking_number_header', function(){ ?> <th class="no-space">Custom Data</th> <?php }, 25 );