修改

library/utils/WxpayV2.php

@@ -249,9 +249,10 @@ class WxpayV2{
         $apiv2Key = $this->config["ApiV2Key"];// 在商户平台上设置的APIv2密钥
         $inBodyArray = Transformer::toArray($inBody);
         var_dump($inBodyArray);
-        ['sign_type' => $signType, 'sign' => $sign] = $inBodyArray;
+        $signType = empty($inBodyArray["sign_type"]) ? Hash::ALGO_MD5 : $inBodyArray["sign_type"];
+        $sign = $inBodyArray["sign"];
         $calculated = Hash::sign(
-            $signType ?? Hash::ALGO_MD5,// 如没获取到`sign_type`，假定默认为`MD5`
+            $signType,// 如没获取到`sign_type`，假定默认为`MD5`
             Formatter::queryStringLike(Formatter::ksort($inBodyArray)),
             $apiv2Key
         );