I'm trying to help a JSON structure format from an existing project, and the goal is to rename some subkeys not the value. The JSON format like this

{
  "table-name": "Kiwi",
  "created-on": "November 20, 2021",
  "token": "lsUVozOB2TxhvMv",
  "icons": "default",
  "links": "default",
  "extra": "default",
  "mode": "Private",
  "collaborators": [],
  "columns": {
    "Name": {
      "type": "text",
      "extra": ""
    },
    "Info": {
      "type": "longtext",
      "extra": ""
    },
    "Status": {
      "type": "droplist",
      "extra": {
        "fr": "Pending",
        "sc": "On-going",
        "th": "Completed",
        "fo": "Cancelled"
      }
    }
  },
  "data": [{
      "Name": "Team Reports",
      "Info": "Submitting marketing materials reports",
      "Status": "Completed"
    },
    {
      "Name": "Fabia HR",
      "Info": "Brian asking for a report",
      "Status": "Pending"
    },
    {
      "Name": "Fabia",
      "Info": "Meeting with CEO @cafe 9:00",
      "Status": "Cancelled"
    }
  ]
}

And we're looking into the columns to rename the Name into Task and still keep the other. After using array push and slice the keys, I'm getting 0 as the keys and "Task as subkeys like

"0":{
  "Task":{
    "type":"text",
    "extra":""
  },

The code looks like this. Please do share your solutions in your spare time, thank you in advance, really appreciate any attention. Total noob here 🖐 PHP:

$file = file.json;  
$jsn = file_get_contents($file);
$data = json_decode($jsn, true);
 
//get name data array 
$sub_data = $data['columns']['Name'];

$new_rename = array(
    "Task" => $sub_data;
);

array_push($data['columns'],$new_rename);

//now delete old "Name";
array_slice($data['columns'],'Name')

//save stuff
$jsn = json_encode($data);
file_put_contents($file,$jsn);