[SOLVED] My Responsive Navbar toggle doesn't work (javascript)

My Responsive Navbar toggle doesn't work (javascript)

I am trying to make a responsive navbar for my project (I am still a newbie learning this). I want to get a dropdown-like nav anchors when I click on the menu bar (3 horizontally parallel lines). I used the Eventlistener and it is not setting that toggle_button to 'active'. I have been going through YouTube videos, some questions on here, and references all over the internet and I cannot seem to find the solution.

Here is my code block.

const toggleButton = document.getElementsByClassName('toggle_btn')[0];
 const navbarLinks = document.getElementsByClassName('navbar_links')[0];

 toggleButton.addEventListener('click', () => {
    navbarLinks.classList.toggle('active')
 });

/*General Styling*/
body {
    overflow: hidden;
    background-color: grey;
    color: #d4af37 ;
    font-size: 20px;
    display: flex;
    justify-content: center;
    min-height: 90vh;
    background: url("images/background.png") no-repeat;
    background-size: cover;
    background-position: center;
    font-family: Baskerville, "Palatino Linotype", Palatino, "Century Schoolbook L", "Times New Roman", "serif";
  }

header{
    display: flex;
    justify-content: space-between;
    align-content: center;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 50px;
    padding: 20px 100px;
}


a{
    padding-right: 10px;
}

nav ul {
    margin: 0;
    padding: 0;
    display: flex;
}
nav li {
    list-style: none;
}
nav li a {
    padding: 1rem;
    display: block;
}


/*Styling using class*/
.nav {
    text-decoration: none;
    color: #d4af37;
    position: relative;
    font-weight: 500;
}

.nav::after{
    content: '';
    position: absolute;
    left: 0;
    bottom: -6px;
    width: 90%;
    height: 1px;
    background: #d4af37;
    border-radius: 5px;
    transform: scaleX(0);
    transition: transform .5s;
}

.nav:hover::after{
    transform: scaleX(1);
}

/*responsive button*/
.toggle_btn {
    position: absolute;
    top: 4.5rem;
    right: 1rem;
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 21px;
    margin-right: 200px;
}

.toggle_btn .bar{
    height: 3px;
    width: 100%;
    background-color: #a1852b;
    border-radius: 10px;
}


/*responsive nav bar*/
@media only screen and (max-width: 600px) {
    .toggle_btn{
        display: flex;
    }
    .navbar_links{
  display:none;
  }
  
  header{
        flex-direction: column;
        align-items: flex-start;
    }

    nav ul{
        width: 100%;
        flex-direction: column;

    }

    nav li{
        padding-left: 4rem;
    }

    nav li a{
        padding: .5rem 1rem;
    }

    nav.active {
        display: flex;
    }
  nav.active .nav{
        display:block;
        width: 100%;
    }
}

<!--Logo and Nav-->
    <header> 
            <!--Logo and brandName-->
            <div id="logo_div"> 
                <img class="images" id="logo" src="images/logo+name.png" alt="Crux Logo and Brand Name here.">
            </div>
                <!--Nav bar-->
            <div id="nav_div">
                
                <!--Nav-bar toggle-->
                <a href="#" class="toggle_btn"> 
                    <span class="bar"> </span>
                    <span class="bar"> </span>
                    <span class="bar"> </span>
                </a>

                <nav class="navbar_links">
                    <ul> 
                        <li><a class="nav" href="#">Home</a></li>
                        <li><a class="nav" href="#">About Us</a></li>
                        <li><a class="nav" href="#">Services</a></li>
                        <li><a class="nav" href="#">Contact</a></li>
                    </ul>
                </nav>
            </div>
    </header>

Solution

Your hamburger menu has a class of toggle_btn, but your JS is looking for elements with class of toggle_button, which don't exist, so your event listener is not being attached to anything.