Replace display name with first name & last name in name value

functions.php

<?php
/**
 * Set custom user variable for WooCommerce Wave Connector
 * Replace display name with first name & last name in name value
 *
 * @param array $variables get variables.
 * @param array $user_ids get user's id.
 * @return array
 */
function custom_customer_variable( $variables, $user_ids ) {
	foreach ( $variables as $key => $variable ) {
		$fname = isset( $variable['firstName'] ) ? $variable['firstName'] : '';
		$lname = isset( $variable['lastName'] ) ? $variable['lastName'] : '';
		$name  = $fname . ' ' . $lname;
		if ( ' ' !== $name ) {
			$variable['name']  = $name;
			$variables[ $key ] = $variable;
		}
	}
	return $variables;
}
add_filter( 'venus_wc_export_customer_variables', 'custom_customer_variable', 10, 2 );