add dropdown menu in theme

 <style>

ul {

  list-style-type: none;

  margin: 0;

  padding: 0;

  overflow: hidden;

  background-color: black;

}

li {

  float: left;

}

li a, .dropbtn {

  display: inline-block;

  color: white;

  text-align: center;

  padding: 14px 16px;

  text-decoration: none;

}

li a:hover, .dropdown:hover .dropbtn {

  background-color: red;

}

li.dropdown {

  display: inline-block;

}

.dropdown-content {

  display: none;

  position: absolute;

  background-color: #f9f9f9;

  min-width: 160px;

  box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);

  z-index: 1;

}

.dropdown-content a {

  color: black;

  padding: 12px 16px;

  text-decoration: none;

  display: block;

  text-align: left;

}

.dropdown-content a:hover {background-color: #f1f1f1;}

.dropdown:hover .dropdown-content {

  display: block;

}

</style>

<ul>

  <li><a href="#">Home</a></li>

  <li><a href="#">Name 1</a></li>

<li><a href="#">Name 2</a></li>

<li><a href="#">Name 3</a></li>

<li><a href="#">Name 4</a></li>

  <li class="dropdown">

    <a href="javascript:void(0)" class="dropbtn">More</a>

    <div class="dropdown-content">

      <a href="#">list 1</a>

      <a href="#">list 2</a>

      

    </div>

  </li>

</ul>