When rendering a menu, in the twig file, you can set a class if item.in_active_trail
is set:
{% for item in items %}
{%
set classes = [
item.in_active_trail ? 'is-active',
]
%}
However this class is applied to each link in the trail - so if you are on the third level, three links get this class.
Is there anything I can see OOTB on item
or add to it if the menu link is the current page? I need to highlight it and not just items in the trail itself.