// 接下来，正常使用Guzzle发起API请求，WechatPayMiddleware会自动地处理签名和验签
$resp = $client->request('POST', 'https://api.mch.weixin.qq.com/v3/ecommerce/applyments/', [
    'josn'    => [
        'organization_type'=>2
    ],
    'headers' => [
        'Content-Type' => 'application/json',
        'Accept'       => 'application/json'
    ]
]);
以上是测试源码