Company used Editor to make Navigation, I want to use WordPress' Navigation inte

Appearance>Menus in the Dashbioard

Create a menu and place it in the location made available by the Theme.

If they hard coded your menu, they may not have put a “location” in your theme to display your custom menu, nor may they have registered it in the functions.php, which is where you tell your Theme how many custom menu locations you can have.

So you need to check two things:

Your functions.php file (never change it without first backing it up)
Look for lines like this:

// Adds support for WP Custom Menus
add_action( 'init', 'register_my_menus' );

function register_my_menus() {
register_nav_menus(
array(
'primary' => __( 'Top Menu' ),
'secondary' => __( 'Footer Left' ),
'tertiary' => __( 'Footer Center' ),
'quaternary' => __( 'Footer Right' )
)
);
}

The names are arbitrary, call them whatever suits your needs – you’re just establishing here HOW MANY menus you want to be ABLE to create under Appearance >Menus – I use names that tell me also at a glance WHERE I plan to put them.

THEN in your Theme’s template files, you have to put the code to call the menu if you create it – so in my header.php file, I have this:

<?php wp_nav_menu( array( 'theme_location' => 'primary' ) ); ?>

And in my footer.php file, I have this:

<?php wp_nav_menu( array( 'theme_location' => 'secondary' ) ); ?>
<?php wp_nav_menu( array( 'theme_location' => 'tertiary' ) ); ?>
<?php wp_nav_menu( array( 'theme_location' => 'quaternary' ) ); ?>

Then you just go to Appearance >Menus and you create a Menu using the SAME names that you put in your functions, e.g. “Top Menu” etc. and add whatever you want in your menu to it, save it, ASSIGN it to a Location, and voila! Your menus will appear where and as you want them.