How to Import a Predefined Sitemap into Webflow Projects for Page Generation

How can I use a predefined sitemap for a new project and import it into Projects so I can generate pages by importing from an external source, rather than relying on a sitemap.xml url? Since the website is brand new, it doesn’t have an XML yet. The goal is to generate the pages once the site has over 45 static pages and folders, and avoid manually creating all of them in Webflow to save time.