How to refresh form after submit in PHP

+10 How to refresh form after submit in PHP index.php <html> <title>Codelizar Form</title> <head> <link rel=”stylesheet” type=”text/css” href=”https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css”> <script type=”text/javascript” src=”https://stackpath.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.min.js”></script> </head> <body> <form method=”POST” action=””> <div class=”row”> <div class=”col-md-3 form-group”> <label for=”username”></label> <input type=”text” value=”” name=”username” class=”form-control”> </div> <div class=”col-md-3 form-group”> <label for=”password”></label> <input type=”text” value=”” name=”password” class=”form-control”> </div> <div class=”col-md-3 form-group”> <button name=”btn_submit” …