Fatal error: Uncaught Error: Call to undefined function add_action() in /home/lawfirmsincyprus/public_html/wp-content/plugins/sf-booking/frontend/modules/invoice/invoice-data.php:449 Stack trace: #0 {main} thrown in /home/lawfirmsincyprus/public_html/wp-content/plugins/sf-booking/frontend/modules/invoice/invoice-data.php on line 449