新gocardless api http错误500

Question

当使用新的无刀片api示例时，我可以列出客户，所以我假设我已经正确安装了作曲家但是当我尝试创建订阅的示例时（如下所示）我得到http错误500是否有人知道我是什么可能做错了？

<?php
require 'vendor/autoload.php';

$client = new \GoCardlessPro\Client(array(
  'access_token' => 'my_sandbox_access_token_goes_here',
  'environment'  => \GoCardlessPro\Environment::SANDBOX
));

$client->subscriptions()->create([
  "params" => ["amount" => 25,
               "currency" => "GBP",
               "name" => "Monthly test",
               "interval_unit" => "monthly",
               "day_of_month" => 1,
               "metadata" => ["order_no" => "test1"],
               "links" => ["mandate" => "MA125"]]
]);
?>

由于