我正在从API接收JSON POST请求。这是我记录请求时得到的结果：

[{
    "Body": {
        "stkCallback": {
            "MerchantRequestID": "13321-2667814-1","CheckoutRequestID": "ws_CO_DMZ_411079791_05112019122517461","ResultCode": 0,"ResultDesc": "The service request is processed successfully.","CallbackMetadata": {
                "Item": [{
                    "Name": "Amount","Value": 10
                },{
                    "Name": "MpesaReceiptNumber","Value": "NK57QKRQ0N"
                },{
                    "Name": "Balance"
                },{
                    "Name": "TransactionDate","Value": 20191105122544
                },{
                    "Name": "PhoneNumber","Value": 254725741968
                }]
            }
        }
    },"secret": "=ffdhdjfhfhjfoooi//khfhf="
}]

我收到的请求如下：

$data = collect([$request])->toJson();

有人可以帮我从JSON中获取值，特别是ResultCode，TransactionDate，PhoneNumber和secret。我是新手，我们将不胜感激