How to implement Server Side DataTable in CI4

Hi i'm trying to implement Server Side Datatable in CI4 but it is not working. I'm not sure what is my mistake is

********************VIEW********************
Name : index.php

Code:

<table class="table table-striped table-bordered table-hover nowrap" id="kt_table_2">

Code:

 <thead>

Code:

     <tr>
       <th>#</th>
       <th>Product Code No</th>
       <th>Part Number</th>
       <th>Description</th>
     </tr>
</thead>
</table>

<script>
$(document).ready(function(){



$('#kt_table_2').DataTable({
"processing": true,
"serverSide": true,
"ajax":{
"url": '/product-code/showProductCodes',
"dataType": "json",
"type": "POST",
"columns": [
  { "data": "product_code_no" },
  { "data": "part_number" },
  { "data": "date_created" }
]
}
});

});

</script>

********************Routes********************

PHP Code:

$routes->add('/product-codes(:any)', 'Code8ProductCode::index'); //This is the Page Itself

$routes->add('/product-code/showProductCodes(:any)', 'Code8ProductCode::showProductCodes'); //This is the Ajax Request 


********************Controller********************
Note : i only show the controller for Ajax request

Code:

public function showProductCodes(){

        
        $columns = array(
            0 =>'product_code_no',
            1 =>'part_number',
            2=> 'date_created',
            3=> 'product_code_no',
        );

        $limit = $this->request->getVar('length');
        $start = $this->request->getVar('start');
        $order = $columns[$this->request->getVar('order')[0]['column']];
        $dir = $this->request->getVar('order')[0]['dir'];
        
        $totalData = $this->Code8ProductCode_model->countAll();
        
        $totalFiltered = $totalData;
        
        if(empty($this->request->getVar('search')['value'])){           
            $records = $this->Code8ProductCode_model->allRecords($limit,$start,$order,$dir);
        }else{
            $search = $this->request->getVar('search')['value'];
            
            $records =  $this->Code8ProductCode_model->recordsSearch($limit,$start,$search,$order,$dir);

            $totalFiltered = $this->Code8ProductCode_model->recordsSearchCount($search);
        }   

        $data = array();
        if(!empty($records))
        {
            foreach ($records as $record)
            {
                $nestedData['product_code_no'] = $record->product_code_no;
                $nestedData['part_number'] = $record->part_number;
                //$nestedData['body'] = substr(strip_tags($record->body),0,50)."...";
                //$nestedData['created_at'] = date('j M Y h:i a',strtotime($record->date_created));
                $nestedData['description'] = $record->description;
                $nestedData['date_created'] = $record->date_created;
               
                $data[] = $nestedData;
            }
        }
        
        $json_data = array(
            "draw"            => intval($this->request->getVar('draw')), 
            "recordsTotal"    => intval($totalData), 
            "recordsFiltered" => intval($totalFiltered),
            "data"            => $data   
            );
           
        return json_encode($json_data);
        

    }//End Function

********************Model********************
Note : i only show the involve function for the DataTable

PHP Code:

function countAll(){   
        $CompanyGroupNo = 3;
        $status = 1;
    
        $sql = "SELECT product_code_no FROM `tbl_pcc_product_code` WHERE `status` = :status: AND `company_group_no` = :CompanyGroupNo:";
        $query = $this->BaseModel->db->query($sql, ['CompanyGroupNo' => $CompanyGroupNo, 'status' => $status]);
        $results = $query->getResultArray();
        
        return count($results);
    }
    
    function allRecords($limit,$start,$col,$dir){   
        $CompanyGroupNo = 3;
        $status = 1;        
                
        $sql = "SELECT * FROM `tbl_pcc_product_code` WHERE `status` = :status: AND `company_group_no` = :CompanyGroupNo: LIMIT :limit:, :start: ORDER BY :col:, :dir:";
        $query = $this->BaseModel->db->query($sql, [
            'CompanyGroupNo' => $CompanyGroupNo,
            'status' => $status, 
            'limit' => $limit, 
            'start' => $start, 
            'col' => $col, 
            'dir' => $dir
        ]);
        $results = $query->getResultArray();    

        if(count($results)>0 ){
            return $results; 
        }else{
            return null;
        }
        
    }
    
    function recordsSearch($limit,$start,$search,$col,$dir){
        $CompanyGroupNo = 3;
        $status = 1;        
                
        $sql = "SELECT * FROM `tbl_pcc_product_code` WHERE `status` = :status: AND `company_group_no` = :CompanyGroupNo: AND part_number LIKE CONCAT('%', :search:,'%') LIMIT :limit:, :start: ORDER BY :col:, :dir:";
        $query = $this->BaseModel->db->query($sql, [
            'CompanyGroupNo' => $CompanyGroupNo,
            'status' => $status, 
            'limit' => $limit, 
            'start' => $start, 
            'col' => $col, 
            'dir' => $dir, 
            'search' => $search
        ]);
        $results = $query->getResultArray();        
        
       
        if(count($results)>0 ){
            return $results; 
        }else{
            return null;
        }
    }
    
    function recordsSearchCount($search){
        $CompanyGroupNo = 3;
        $status = 1;
        
        $sql = "SELECT product_code_no FROM `tbl_pcc_product_code` WHERE `status` = :status: AND `company_group_no` = :CompanyGroupNo: AND part_number LIKE CONCAT('%', :search:,'%') ";
        $query = $this->BaseModel->db->query($sql, [
            'CompanyGroupNo' => $CompanyGroupNo,
            'status' => $status, 
            'search' => $search
        ]);    
        
        $results = $query->getResultArray();
        return count($results);
    } 


Thanks,