ticket_id_export.php

add_action( 'tribe_events_tickets_generate_filtered_attendees_list', 'tec_extend_ticket_export' );
/**
 * Extend the ticket export to include the Ticket ID for each of the tickets
 */
function tec_extend_ticket_export( $event_id ) {

	if ( ! is_admin() ) {
		$screen_base = 'tribe_events_page_tickets-attendees';
	} else {
		$screen      = get_current_screen();
		$screen_base = $screen->base;
	}
	$filter_name = "manage_{$screen_base}_columns";

	add_filter( $filter_name, 'tec_add_ticket_id_column', 20 );
	add_filter( 'tribe_events_tickets_attendees_table_column', 'tec_populate_ticket_id_column', 10, 3 );

}

function tec_add_ticket_id_column( $columns ) {

	$columns['ticket_id'] = 'Ticket ID';

	return $columns;
}

function tec_populate_ticket_id_column( $existing, $item, $column ) {

	if( $column == 'ticket_id' ) {
		return $item['attendee_id'];
	}

	return $existing;

}