Remove WordPress menus

functions.php

<?php 
function remove_item_from_menu() {
    remove_menu_page( 'edit.php?post_type=elementor_library' ); // removes elementor addons , menu item added by plugins
    remove_menu_page( 'edit-comments.php' ); // removes comment menu
    remove_submenu_page('themes.php', 'theme-editor.php'); // remove submenu called theme edititor inside appearance
    remove_submenu_page('themes.php', 'widgets.php'); // removes widgets submenu
}
add_action( 'admin_init', 'remove_item_from_menu' );