This repo contains sample implementations for rendering Notion blocks with React.
It's not a package, which means that this is not a ready to use code, but more something to take inspiration from, maybe copy-paste it, but for sure adapted to your use case. It doesn't cover the implementation of all the available blocks, but only the ones I personally used. There's no styling, because that of course will differ all the time.
I wrote how I used this code in this blog post.