Overview

There are several ways to create a sitemap in Nuxt 3, so here are my notes.

[1] @nuxtjs/sitemap

Documentation

Introduction
Sitemap Module for Nuxt
Nuxt Sitemap Module

Reference Article

@nuxt/sitemapで動的にサイトマップを作る
Zenn

Installation

npm install -D @nuxtjs/sitemap

Repository

GitHub - nuxt-community/sitemap-module: Sitemap Module for Nuxt 2
Sitemap Module for Nuxt 2. Contribute to nuxt-community/sitemap-module development by creating an account on GitHub.
GitHub

[2] sitemap

Reference Article

【Nuxt3】SSGモードでxmlサイトマップを作成する方法【動的ページ対応】
Zenn

Installation

npm install -D sitemap

Repository

GitHub - ekalinin/sitemap.js: Sitemap-generating framework for node.js
Sitemap-generating framework for node.js. Contribute to ekalinin/sitemap.js development by creating an account on GitHub.
GitHub

[3] nuxt-simple-sitemap

This package has the following note, so using @nuxtjs/sitemap from [1] seems to be the better choice:

Package has been migrated to @nuxtjs/sitemap.

www.npmjs.com
www.npmjs.com

Documentation

nuxt.com
nuxt.com

Reference Article

Nuxt3でサイトマップを生成する | Shinobi Works（シノビワークス）
Nuxt3でサイトマップが生成できるモジュール、Simple-Sitemapが公開されました。難しい設定不要で、動的ルーティング含め、ちゃんとしたsitemap.xmlが.output/publicフォルダ内に生成されます。
Shinobi Works（シノビワークス）

Installation

npm install --save-dev nuxt-simple-sitemap

Repository

GitHub - nuxt-modules/sitemap: Powerfully flexible XML Sitemaps that integrate seamlessly, for Nuxt.
Powerfully flexible XML Sitemaps that integrate seamlessly, for Nuxt. - nuxt-modules/sitemap
GitHub

Summary

There may be other options, but I hope this serves as a useful reference.