index.js

/* When the user clicks on the button,
toggle between hiding and showing the dropdown content */
function myFunction() {
    document.getElementById("myDropdown").classList.toggle("show");
}

// Close the dropdown menu if the user clicks outside of it
window.onclick = function (event) {
    if (!event.target.matches('.dropbtn')) {
        var dropdowns = document.getElementsByClassName("dropdown-content");
        var i;
        for (i = 0; i < dropdowns.length; i++) {
            var openDropdown = dropdowns[i];
            if (openDropdown.classList.contains('show')) {
                openDropdown.classList.remove('show');
            }
        }
    }
}

const navbarlinks = document.getElementsByClassName('links')[0]
const toggleButton = document.getElementsByClassName('toggle_button')[0]
document.getElementsByClassName('toggle_button')[0].addEventListener('click', () => {
    navbarlinks.classList.toggle('active')
})