I am trying to implement a file upload form in which files are saved. I had written the following code

<?php  /**  * @file  * Contains Drupalavenue_product_importFormavenue_product_importForm.  */  namespace Drupalavenue_product_importForm;  use DrupalCoreFormFormBase; use DrupalCoreFormFormStateInterface; use DrupalfileEntityFile;  class AvenueForm extends FormBase {    public function getFormId() {     return 'AvenueForm';   }     public function buildForm(array $form, FormStateInterface $form_state) {      $form['description'] = [       '#markup' => '<p>Use this form to upload a CSV file of Data</p>',     ];      $form['import_csv'] = [       '#type'              => 'managed_file',       '#title'             => t('Upload file here'),       '#upload_location'   => 'public://importcsv/',       '#default_value'     => '',       "#upload_validators" => ["file_validate_extensions" => ["csv"]],       '#states'            => [         'visible' => [           ':input[name="File_type"]' => ['value' => t('Upload Your File')],         ],       ],     ];      $form['actions']['#type'] = 'actions';       $form['actions']['submit'] = [       '#type'        => 'submit',       '#value'       => $this->t('Upload CSV'),       '#button_type' => 'primary',     ];      return $form;   }    public function submitForm(array &$form, FormStateInterface $form_state) {      /* Fetch the array of the file stored temporarily in database */     $csv_file = $form_state->getValue('import_csv');      /* Load the object of the file by it's fid */     $file = File::load($csv_file[0]);      /* Set the status flag permanent of the file object */     $file->setPermanent();      /* Save the file in database */     $file->save();      drupal_set_message('File Uploaded Successfully');   }  } 

But here the problem is if the filename in which I am uploading is same. It is getting renamed. But I want to replace old with the new one. How can I achieve this? I had seen file_move() and file_save_upload() function. What changes should I make to replace existing filename with the newly uploaded CSV file?