From 7a29436145b1f59b8a2af464fc00346ef4871e6e Mon Sep 17 00:00:00 2001
From: JordenPowleyWebDev
 <31571981+JordenPowleyWebDev@users.noreply.github.com>
Date: Wed, 18 May 2022 09:17:02 +0100
Subject: [PATCH] Update src/OAuth2.php

Co-authored-by: Stephen J Sullivan <60765965+SteJaySulli@users.noreply.github.com>
---
 src/OAuth2.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/OAuth2.php b/src/OAuth2.php
index 58ce0aa..5d066bb 100644
--- a/src/OAuth2.php
+++ b/src/OAuth2.php
@@ -130,7 +130,7 @@ public function getTenants(AccessTokenInterface $accessToken)
      * @param string|null $grantType
      * @return AccessTokenInterface
      */
-    public function refreshAccessToken(AccessTokenInterface $accessToken, string $grantType = null)
+    public function refreshAccessToken(AccessTokenInterface $accessToken, string? $grantType = null)
     {
         $body = [
             'refresh_token' => $accessToken->getRefreshToken()