Method not allowed on Delete

1

Method not allowed when Trying to deletes users
Also Message checkbox confirmation when delete not Showing

Controller :

 public function deleteselected()
 {
    $this->request->allowMethod(['user', 'delete']);
    $data = $this->request->getData('ids');
    foreach ($data as $value) {
        $this->Users->deleteAll(['id'=>$value]);
    }
    return $this->redirect(['action'=>'index']);
  }

Script :

<script>
 $('.selectall').click(function(){
 $('.selectbox').prop('checked',$(this).prop('checked'));
 $('.selectall2').prop('checked',$(this).prop('checked'));
 });
$('.selectall2').click(function(){
$('.selectbox').prop('checked',$(this).prop('checked'));
$('.selectall').prop('checked',$(this).prop('checked'));
});
$('.selectbox').click(function(){
var total = $('.selectbox').length;
var number = $('.selectbox:checked').length;
if(total == number){
    $('.selectall').prop('checked', true);
    $('.selectall2').prop('checked', true);
}else {
    $('.selectall').prop('checked', false);
    $('.selectall2').prop('checked', false);
}});
</script>

Button :

 <form method="user">
    <p>
 <button type="submit" formaction="<?php echo $this->Url- 
 >build(['action'=>'deleteselected']) ?>" class="btn btn-danger">Delete Selected</button>
    </p> 

        <tr>
            <th><input type="checkbox" class="selectall"/></th>
       </tr>


  <td><input type="checkbox" class="selectbox" name="ids[]" value="<?php echo $user->id ?>" 
   /></td>

 <button type="submit" formaction="<?php echo $this->Url->build(['action' 
 =>'delete', $user->id]) ?>" class="btn btn-danger" onclick="return 
 confirm('Are you sure?)">Delete</button>