I'm having difficulty moving items on my Navbar to either end. At the moment I have this:

I would like to move the flag image next to the toggler button, it is only there when the breakpoint reaches the Navbar button size, 992px.
I'm sure the Bootstrap Stylesheet is aligning it using justify-content: space-between; I have tried using align-self: flex-end !important; on both flag and button as well as using justify-content-end
Codepen - https://codepen.io/jvern22/pen/gZjJBN
My Nav code;
<div class="container container-navbar">
<a class="navbar-brand" href="index.php">Website title</a>
<a class="navbar-brand justify-content-end" href="#"><img src="assets/img/spain.png" class="navbar-flag"></a>
<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#top-navbar-1" aria-controls="top-navbar-1" aria-expanded="true" aria-label="Toggle navigation">
<span class="navbar-toggler-icon"></span>
</button>
<!-- Collect the nav links, forms, and other content for toggling -->
<div class="collapse navbar-collapse" id="top-navbar-1">
<ul class="navbar-nav justify-content-end">
<li class="nav-item"><a class="nav-link" href="?page=taketour"><?php echo $lang['nav_takeatour']; ?></a></li>
<li class="nav-item"><a class="nav-link" href="?page=websites"><?php echo $lang['nav_websites']; ?></a></li>
</ul>
</div>
</div>
</nav>