This is an inline navbar for bootstrap 4 + my custom classes.
<nav class="navbar navbar-expand-lg navbar-light white no-margin-bottom">
<div class="container">
<a class="navbar-brand no-pad no-margin-top no-margin-right" href="">
<img src="" class="header-logo no-pad-top no-margin-top" alt="">
</a>
<button class="navbar-toggler custom-toggler" type="button" data-toggle="collapse" data-target="#navbar-content" aria-controls="navbar-content" aria-expanded="false" aria-label="<?php esc_html_e( 'Toggle Navigation', 'theme-textdomain' ); ?>">
<span class="navbar-toggler-icon"></span>
</button>
<div class="collapse navbar-collapse text-center" id="navbar-content">
<?php
wp_nav_menu( array(
'theme_location' => 'primary',
'menu_id' => 'primary-menu',
'container' => false,
'depth' => 2,
'menu_class' => 'navbar-nav ml-auto',
'walker' => new Bootstrap_NavWalker(),
'fallback_cb' => 'Bootstrap_NavWalker::fallback',
) );
?>
</div>
</div>
</nav>