How to remove/add Language Menu from header

First go to site’s file manager and goto:

public_html/wp-content/themes/foxiz/header.php

Replace below code to remove Language Menu

<?php
/** Don't load directly */
defined( 'ABSPATH' ) || exit;

?><!DOCTYPE html>
<html <?php language_attributes();
if ( foxiz_is_amp() ) {
	echo ' [class]="collapse ? \'collapse-activated\' : \'collapse-deactivated\'"';
} ?>>
<head>
    <meta charset="<?php bloginfo( 'charset' ); ?>" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
	<meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="profile" href="https://gmpg.org/xfn/11" />
	<?php wp_head(); ?>
</head>
<body <?php body_class(); ?> data-theme="<?php echo foxiz_get_theme_mode(); ?>">
<?php
wp_body_open();
foxiz_top_ad();
?><div class="site-outer">
	<?php foxiz_render_header(); ?>
    <div class="site-wrap">

Replace below code to add Language Menu again

<?php
/** Don't load directly */
defined( 'ABSPATH' ) || exit;
?>
<!DOCTYPE html>
<html <?php language_attributes();
if ( foxiz_is_amp() ) {
    echo ' [class]="collapse ? \'collapse-activated\' : \'collapse-deactivated\'"';
} ?>>
<head>
	<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-36KYBQFH22"></script>
<meta name="google-site-verification" content="PCzxRdiFZxLyuSysXxnMdKyv9LJK2dnhmTuecWGOHWQ" />
	<script>
	
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'G-36KYBQFH22');
</script>
    <meta charset="<?php bloginfo( 'charset' ); ?>" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <link rel="profile" href="https://gmpg.org/xfn/11" />
    <?php wp_head(); ?>

    <!-- 🌐 Language Switcher Styling -->
    <style>
        .language-menu-wrapper {
    position: absolute;
    top: 10px;
    right: 250px;
    z-index: 9999;
}

.language-menu {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 10px;
}

.language-menu li {
    position: relative;
}

.language-menu li a {
    text-decoration: none;
    background-color: #f1f1f1;
    padding: 4px 10px;
    border-radius: 4px;
    border: 1px solid #ccc;
    font-weight: bold;
    color: #333;
    transition: all 0.3s ease;
    display: block;
    white-space: nowrap;
    box-sizing: border-box;
}

/* Hover Effect */
.language-menu li a:hover {
    background-color: #ED230D;
    color: #fff;
    border-color: #ED230D;
}

/* Hover effect only on actual items, not by default */
.language-menu li ul.sub-menu li a:hover {
    background-color: #ED230D;
    color: #fff;
    border-color: #ED230D;
}

/* Default hidden */
.language-menu li ul.sub-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: #f9f9f9;
    padding: 0;
    border: 1px solid #ccc;
    border-radius: 4px;
    z-index: 1000;
    min-width: 100%; /* Always match parent width */
    width: max-content;
    box-sizing: border-box;
}

/* Fix width of submenu items */
.language-menu li ul.sub-menu li a {
    display: block;
    width: 100%;
    padding: 6px 10px;
    box-sizing: border-box;
}

/* Arrow ▼ for parent */
.language-menu li.menu-item-has-children > a::after {
    content: " ▼";
    font-size: 11px;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
    .language-menu-wrapper {
        top: 4px;
        right: 100px;
    }

    .language-menu {
        flex-direction: column;
        gap: 5px;
    }

    .language-menu li ul.sub-menu {
        position: static;
        border: none;
        background: none;
        padding: 0;
        width: 100%;
    }

    .language-menu li ul.sub-menu li a {
        padding: 4px 8px;
        font-size: 13px;
    }

    .language-menu li a {
        font-size: 13px;
        padding: 3px 8px;
    }
}

    </style>
</head>

<body <?php body_class(); ?> data-theme="<?php echo foxiz_get_theme_mode(); ?>">
<?php
wp_body_open();
foxiz_top_ad();
?>

<div class="site-outer">

    <!-- 🌐 Language Switcher Menu -->
    <div class="language-menu-wrapper">
        <?php
        wp_nav_menu(array(
            'theme_location' => '',
            'menu' => 'Language Menu', // 👈 Use your menu name
            'container' => false,
            'menu_class' => 'language-menu',
            'fallback_cb' => false
        ));
        ?>
    </div>

    <?php foxiz_render_header(); ?>

    <div class="site-wrap">

    <!-- 🌐 Dropdown Toggle Script -->
    <script>
document.addEventListener("DOMContentLoaded", function () {
    const parentItem = document.querySelector(".language-menu > li.menu-item-has-children");
    const parentLink = parentItem?.querySelector("a");
    const submenu = parentItem?.querySelector(".sub-menu");

    if (parentLink && submenu) {
        // Toggle submenu on clicking "भाषा"
        parentLink.addEventListener("click", function (e) {
            e.preventDefault();
            const isVisible = submenu.style.display === "block";
            submenu.style.display = isVisible ? "none" : "block";
        });

        // Close submenu when clicking outside
        document.addEventListener("click", function (e) {
            if (!parentItem.contains(e.target)) {
                submenu.style.display = "none";
            }
        });
    }
});
</script>