delete all content in laravel project

i want to delete all content from the table in database using a delete method with a url Route::post('delete','receiptcontroller'); but I got an error Invalid route action: [App\Http\Controllers\receiptcontroller]. the view :

 <form action="">
            <input type="submit" value="delete" class="btn-danger btn-lg">
  </form>

and method:

 public function delete()
{
receipt::truncate();

}

via Chebli Mohamed