How to insert a navbar include in the Twig layout

What is the correct way to include a navbar include in the main page, Twig?

I created the layout.twig where you are rendering the div container correctly:

<div class="container">
    {% block content %}{% endblock %}
</div>

I want to insert the Navbar above the div class container

I'm using the following statement:

{% include '_menu.twig' %}

The _menu.twig file is in the same directory as the layout.twig, but displays the following error:

  

Message: Unable to find template "_menu.twig"

What is the right way?