Toggler button in bootstrap4 code not collapsing when I click on it

HTML-CSS
1

When I click on the button , all of my navbar links should collapse to a vertical position. That doesn’t appear to be happening in my case when I reduce the width of the window for my bootstrap webpage. Here is my codepen link to all of my bootstrap4 and html-css code. https://codepen.io/noblegas/pen/OJLdqQW

2

I only recently joined and have not had a chance to go through the courses to figure out how it guides you, but to use the bootstrap css and get the functionality you want requires JQuery and Bootstrap JS for support. I just added these two lines to your head section and it seems to have solved your predicament:

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.4.0/js/bootstrap.min.js"></script>
3

thanks that worked. Only thing I needed to change was update it for my version of bootstrap which was 4.1.1