How to receive the data from WooCommerce API Webhooks - json

Question

Delivery method is Post with a secret;
Delivery url: www.domain2.com/wc_back.php.
The data is json:
{
"order":{
"id":623,
"order_number":623,
"order_key":"wc_order_57224dc67c4ec",
"created_at":"2016-04-28T17:52:06Z",
"updated_at":"2016-04-28T17:52:06Z",
"completed_at":"2016-04-28T17:52:06Z",
"status":"on-hold",
"currency":"USD",
"total":"23.00",
"subtotal":"23.00",
"total_line_items_quantity":1,
"total_tax":"0.00",
"total_shipping":"0.00",
"cart_tax":"0.00",
"shipping_tax":"0.00",
"total_discount":"0.00",
"shipping_methods":"",
"payment_details":{
"method_id":"bacs",
"method_title":"u4ebau6c11u5e01u4ed8u6b3euff08u5faeu4fe1/u652fu4ed8u5b9duff09",
"paid":false
},
"billing_address":{
"first_name":"test",
"last_name":"test",
"company":"",
"address_1":"",
"address_2":"",
"city":"",
"state":"",
"postcode":"",
"country":"US",
"email":"test#163.com",
"phone":""
},
"shipping_address":{
"first_name":"test",
"last_name":"test",
"company":"",
"address_1":"",
"address_2":"",
"city":"",
"state":"",
"postcode":"",
"country":"US"
},
"note":"",
"customer_ip":"192.200.194.126",
"customer_user_agent":"Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.87 Safari/537.36",
"customer_id":0,
"view_order_url":"http://www.domain.com/my-account/view-order/623",
"line_items":[
{
"id":151,
"subtotal":"23.00",
"subtotal_tax":"0.00",
"total":"23.00",
"total_tax":"0.00",
"price":"23.00",
"quantity":1,
"tax_class":null,
"name":"u5251u7075u7f8eu670du91d1u5e01100G",
"product_id":26,
"sku":"bnsus100g",
"meta":[
]
}
],
"shipping_lines":[
],
"tax_lines":[
],
"fee_lines":[
],
"coupon_lines":[
],
"customer":{
"id":0,
"email":"test#163.com",
"first_name":"test",
"last_name":"test",
"billing_address":{
"first_name":"test",
"last_name":"test",
"company":"",
"address_1":"",
"address_2":"",
"city":"",
"state":"",
"postcode":"",
"country":"US",
"email":"test#163.com",
"phone":""
},
"shipping_address":{
"first_name":"test",
"last_name":"test",
"company":"",
"address_1":"",
"address_2":"",
"city":"",
"state":"",
"postcode":"",
"country":"US"
}
}
}
}
I receive the data on another website www.domain2.com/wc_back.php.
I don't know how, and I need someone help me to make it.
I want to receive the data stored into a txt file as formatted json variables.
If you need a recompense, we can negotiate it.