Fix PHPCS

src/Handler.php

@@ -840,7 +840,7 @@ class Handler extends BaseHandler {
    * @return string|array
    *   The ipv4 address(es).
    */
-  private function getLocalIpv4(string $interface = NULL): array|string {
+  private function getLocalIpv4(?string $interface = NULL): array|string {
     $out = explode(PHP_EOL, shell_exec('LC_ALL=C /sbin/ifconfig'));
     $local_addrs = [];
     $ifname = 'unknown';