$request- session()- regenerate() laravel code example
Example: laravel session flash 2020
use Illuminate\Support\Facades\Session;
Session::flash('message','This is a message!');
then in your view::
@if(Session::has('message'))
<p class="alert
{{ Session::get('alert-class', 'alert-info') }}">{{Session::get('message') }}</p>
@endif