navbar.php

<nav class="navbar navbar-expand-lg navbar-dark bg-dark shadow-lg p-3 mb-5 ">
  <a class="navbar-brand" href="#">NGO</a>
  <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="index.php" aria-controls="navbarNav" aria-expanded="false" aria-label="Toggle navigation">
    <span class="navbar-toggler-icon"></span>
  </button>
  <div class="collapse navbar-collapse" id="navbarNav">
    <ul class="navbar-nav">
      <li class="nav-item active">
        <a class="nav-link" href="#">Please Login To Continue <span class="sr-only">(current)</span></a>
      </li>
     
      <li class="nav-item dropdown">
        <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
          Login Here
        </a>
        <div class="dropdown-menu" aria-labelledby="navbarDropdown">
          <a class="dropdown-item" href="login/adminLogin.php">Admin</a>
          <a class="dropdown-item" href="login/donorLogin.php">Donor</a>
          <a class="dropdown-item" href="login/volunteerLogin.php">Volunteer</a>
        </div>
      </li>
    </ul>
  </div>
</nav>