Notion as a CMS
This repo is a great example of how render data from a private notion page with NextJS. The data is fetched at build time and refetched in the background using SSG. This example has basically reversed engineered the notion api since there is no official API available, yet.
This blog post explains how to use NextJS and react-notion to render public notion pages. They also use notion-api-worker to cache API responses. Although this isn't as important if the data is fetched in the background with SSG.