How to Hide WP Frontend Admin Admin Menus

function plt_hide_display_admin_page_on_frontend_menus() {
	//Hide "Frontend Admin".
	remove_menu_page('wpatof_welcome_page');
	//Hide "Frontend Admin → Frontend Admin".
	remove_submenu_page('wpatof_welcome_page', 'wpatof_welcome_page');
	//Hide "Frontend Admin → Settings".
	remove_submenu_page('wpatof_welcome_page', 'vg_admin_to_frontend');
	//Hide "Frontend Admin → Contact Us".
	remove_submenu_page('wpatof_welcome_page', 'wpatof_welcome_page-contact');
	//Hide "Frontend Admin → Upgrade".
	remove_submenu_page('wpatof_welcome_page', 'wpatof_welcome_page-pricing');
}

add_action('admin_menu', 'plt_hide_display_admin_page_on_frontend_menus', 1000000000);

Where do I put this code?