apply_filters( 'navigation_markup_template', string $template, string $class )

Description

Note: The filtered template HTML must contain specifiers for the navigation class (%1$s), the screen-reader-text value (%2$s), and placement of the navigation links (%3$s):

<nav class="navigation %1$s" role="navigation">
    <h2 class="screen-reader-text">%2$s</h2>
    <div class="nav-links">%3$s</div>
</nav>