ok

app/Libs/Pay/Merchants/Official.php

@@ -79,7 +79,7 @@ class Official implements PayMerchantInterface
                     break;
                 case 'APP':
                     $data = [
-                        'appId' => $result->appid,
+                        'appid' => $result->appid,
                         'partnerid' => $result->mch_id,
                         'prepayid' => $result->prepay_id,
                         'package' => "Sign=WXPay",