Why are the menu locations not showing?

If menu locations are not showing up, that's usually because your theme is not registering any menu location.

To fix it, register the menu locations from your theme (typically in the theme's functions.php) by calling register_nav_menus:

register_nav_menus([
    'primary' => __('Header', 'my-theme'),
    'secondary' => __('Footer', 'my-theme'),
]);Copy

Once the theme registers at least one menu location, it will be available to be assigned to a menu, and you will be able to translate menus by their location.