How to Hide VoxAI - AI Audio & Summary for Posts Admin Menus

function plt_hide_voxai_ai_audio_summary_for_posts_menus() {
	//Hide the "VoxAI" menu.
	remove_menu_page('voxaiau');
	//Hide the "VoxAI → Settings" menu.
	remove_submenu_page('voxaiau', 'voxaiau');
	//Hide the "VoxAI → Upgrade to Pro" menu.
	remove_submenu_page('voxaiau', 'voxaiau-pro');
}

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

Where do I put this code?