How to Hide Easy Custom Js And Css Admin Menus

function plt_hide_easy_custom_js_and_css_menus() {
	//Hide "Custom JS & CSS".
	remove_menu_page('easy_custom_js_and_css');
	//Hide "Custom JS & CSS → All Items".
	remove_submenu_page('easy_custom_js_and_css', 'easy_custom_js_and_css');
	//Hide "Custom JS & CSS → All filters".
	remove_submenu_page('easy_custom_js_and_css', 'easy_custom_js_and_css_filters');
	//Hide "Custom JS & CSS → Settings".
	remove_submenu_page('easy_custom_js_and_css', 'easy_custom_js_and_css_settings');
}

add_action('admin_menu', 'plt_hide_easy_custom_js_and_css_menus', 11);

Where do I put this code?