public static function check_voucher_duplicate() {

		$post_id = ! empty( $_REQUEST['postId'] ) ? absint( llms_filter_input( INPUT_POST, 'postId', FILTER_SANITIZE_NUMBER_INT ) ) : 0;
		$codes   = ! empty( $_REQUEST['codes'] ) ? llms_filter_input_sanitize_string( INPUT_POST, 'codes', array( FILTER_REQUIRE_ARRAY ) ) : array();

		if ( ! $post_id || ! $codes ) {
			return new WP_Error( 400, __( 'Missing required parameters', 'lifterlms' ) );
		} elseif ( ! current_user_can( 'edit_post', $post_id ) ) {
			return new WP_Error( 401, __( 'Missing required permissions to perform this action.', 'lifterlms' ) );
		}

		$codes = implode(
			',',
			array_map(
				function( $code ) {
					return sprintf( "'%s'", esc_sql( $code ) );
				},
				array_filter( $codes )
			)
		);

		global $wpdb;
		$table = $wpdb->prefix . 'lifterlms_vouchers_codes';
		$res   = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT code FROM $table WHERE code IN( $codes ) AND voucher_id != %d", // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared
				array( $post_id )
			),
			ARRAY_A
		);

		wp_send_json(
			array(
				'success'    => true,
				'duplicates' => $res,
			)
		);
		wp_die();

	}