在Angular 7数据表中显示数据的问题

Question

I am trying to show the data from my api to my datatable on angular.Api is working fine but i am not able to show that data on my datatable when i click on search button nothing appears in my data tables but data shows on console

Here is ma .ts file code

fetchRollHeader(){
   var apiurl = 'http://localhost/abc/Controller/abc.php';

    var data = new FormData();
    data.append('data', 'fetchRollHeader');
    data.append('roll_id', this.roll_id_start);

      return this.http.post<any>(apiurl, data)

          .pipe(map(response => response))
          .subscribe(
                data=> {
              if(data['response_type'] != undefined && data['response_type'] == 'Error'){

                    if(data['response'] == 29){
                    }else if(data['response'] == 8 || data['response'] == 9 || data['response'] == 10){
                      this.router.navigate(['login']);
                    }else{
                      alert(data['response_value']);


                    }
                }else{
                  this.customers = data;




                }
                 console.log(data);

                },
                error => {
                    console.log("Error", error);
                }
            ); 
  }

Here is my .html file

table datatable class="row-border hover"  style="border:1px solid #f3f3f3">
  <thead>
    <tr >
      <th>ID</th>
      <th>First name</th>
      <th>Last name</th>
    </tr>
  </thead>
  <tbody >
    <tr  *ngFor="let item of customers"   >
      <td >{{item.id}}</td>
      <td >{{item.machine_id}}</td>
      <td >{{item.machine_id}}</td>

      <td>Bar</td>
    </tr>

  </tbody>
</table>

Console Data