Code snippet that can be used to get Taxonomy Term URL Path From a Reference Field -in Twig in Drupal 8.
In Twig, all you need to do is this:
<a href="{{ path('entity.taxonomy_term.canonical', {'taxonomy_term': node.field_taxonomy_reference.entity.tid.value}) }}">
<h2>{{ content.field_taxonomy_reference }}</h2>
</a>
