如何接收POST请求中的JSON对象并同步指定数据至Firebase数据库

我已配置好支付方式，该方式会通过POST请求发送JSON格式的交易数据。我需要接收这些数据，并将其中的指定字段同步至Firebase数据库。

交易处理回调（Transaction Processed Callback） #

这是你Web应用中的一个端点URL，客户完成支付流程后，你会在此收到回调通知。你将在POST请求中收到一个JSON对象，其中包含交易状态（成功/失败）、关联订单ID、交易ID等各类交易相关信息。以下是交易处理回调端点收到的示例请求：

{  
  "obj": {    
    "id": 2556706,    
    "pending": false,    
    "amount_cents": 100,    
    "success": true,    
    "is_auth": false,    
    "is_capture": false,    
    "is_standalois_capturene_payment": true,    
    "is_voided": false,    
    "is_refunded": false,    
    "is_3d_secure": true,    
    "integration_id": 6741,    
    "profile_id": 4214,    
    "has_parent_transaction": false,    
    "order": {      
      "id": 4778239,      
      "created_at": "2020-03-25T18:36:05.494685",      
      "delivery_needed": true,      
      "merchant": {        
        "id": 4214,        
        "created_at": "2019-09-22T18:32:56.764441",        
        "phones": [          
          "01032347111"        
        ],        
        "company_emails": [          
          "fnjum@temp-link.net"        
        ],        
        "company_name": "Accept Payments",        
        "state": "",        
        "country": "EGY",        
        "city": "",        
        "postal_code": "",        
        "street": ""      
      },      
      "collector": {        
        "id": 115,        
        "created_at": "2019-06-29T00:48:26.910433",        
        "phones": [],        
        "company_emails": [],        
        "company_name": "logix - test",        
        "state": "Heliopolis",        
        "country": "egypt",        
        "city": "cairo",        
        "postal_code": "123456",        
        "street": "Marghany"      
      },      
      "amount_cents": 2000,      
      "shipping_data": {        
        "id": 2558893,        
        "first_name": "abdulrahman",        
        "last_name": "Khalifa",        
        "street": "Wadi el Nile",        
        "building": "5",        
        "floor": "11",        
        "apartment": "1565162",        
        "city": "Cairo",        
        "state": "Cairo",        
        "country": "EG",        
        "email": "abdulrahman@weaccept.co",        
        "phone_number": "01011994353",        
        "postal_code": "",        
        "extra_description": " ",        
        "shipping_method": "UNK",        
        "order_id": 4778239,        
        "order": 4778239      
      },      
      "shipping_details": {        
        "id": 1401,        
        "cash_on_delivery_amount": 0,        
        "cash_on_delivery_type": "Cash",        
        "latitude": null,        
        "longitude": null,        
        "is_same_day": 0,        
        "number_of_packages": 1,        
        "weight": 1,        
        "weight_unit": "Kilogram",        
        "length": 1,        
        "width": 1,        
        "height": 1,        
        "delivery_type": "PUD",        
        "return_type": null,        
        "order_id": 4778239,        
        "notes": "im so tired",        
        "order": 4778239      
      },      
      "currency": "EGP",      
      "is_payment_locked": false,      
      "is_return": false,      
      "is_cancel": false,      
      "is_returned": false,      
      "is_canceled": false,      
      "merchant_order_id": null,      
      "wallet_notification": null,      
      "paid_amount_cents": 100,      
      "notify_user_with_email": false,      
      "items": [],      
      "order_url": "https://accept.paymobsolutions.com/i/nYWD",      
      "commission_fees": 0,      
      "delivery_fees_cents": 0,      
      "delivery_vat_cents": 0,      
      "payment_method": "tbc",      
      "merchant_staff_tag": null,      
      "api_source": "OTHER",      
      "pickup_data": null,      
      "delivery_status": []    
    },    
    "created_at": "2020-03-25T18:39:44.719228",    
    "transaction_processed_callback_responses": [],    
    "currency": "EGP",    
    "source_data": {      
      "pan": "2346",      
      "type": "card",      
      "sub_type": "MasterCard"    
    },    
    "api_source": "IFRAME",    
    "terminal_id": null,    
    "is_void": false,    
    "is_refund": false,    
    "data": {      
      "acq_response_code": "00",      
      "avs_acq_response_code": "Unsupported",      
      "klass": "VPCPayment",      
      "receipt_no": "008603626261",      
      "order_info": "claudette09@exa.com",      
      "message": "Approved",      
      "gateway_integration_pk": 6741,      
      "batch_no": "20200325",      
      "card_num": null,      
      "secure_hash": "832F4673452F9538CCD57D6B07B74183A0EEB1BEF7CA58704E31B244E8366549",      
      "avs_result_code": "Unsupported",      
      "card_type": "MC",      
      "merchant": "TEST999999EGP",      
      "created_at": "2020-03-25T16:40:37.127504",      
      "merchant_txn_ref": "6741_572e773a5a0f55ff8de91876075d023e",      
      "authorize_id": "626261",      
      "currency": "EGP",      
      "amount": "100",      
      "transaction_no": "2090026774",      
      "txn_response_code": "0",      
      "command": "pay"    
    },    
    "is_hidden": false,    
    "payment_key_claims": {      
      "lock_order_when_paid": true,      
      "integration_id": 6741,      
      "billing_data": {        
        "email": "claudette09@exa.com",        
        "building": "8028",        
        "apartment": "803",        
        "street": "Ethan Land",        
        "country": "CR",        
        "state": "Utah",        
        "last_name": "Nicolas",        
        "first_name": "Clifford",        
        "postal_code": "01898",        
        "extra_description": "NA",        
        "phone_number": "+86(8)9135210487",        
        "floor": "42",        
        "city": "Jaskolskiburgh"      
      },      
      "order_id": 4778239,      
      "user_id": 4705,      
      "pmk_ip": "197.57.37.135",      
      "exp": 1585157836,      
      "currency": "EGP",      
      "amount_cents": 100    
    },    
    "error_occured": false,    
    "is_live": false,    
    "other_endpoint_reference": null,    
    "refunded_amount_cents": 0,    
    "source_id": -1,    
    "is_captured": false,    
    "captured_amount": 0,    
    "merchant_staff_tag": null,    
    "owner": 4705,    
    "parent_transaction": null  
  },  
  "type": "TRANSACTION"
}

内容的提问来源于stack exchange，提问作者ahmed metwali