Relational vs non-relation is one of the biggest misconceptions about NoSQL
Data is usually relational, there's no getting away from that just because of the database you use. NoSQL can manage all kinds of relations, just with an extremely different approach.
If you're interested in learning how this works instead of repeating the tired meme of "mongodb lol" checkout Alex Debrie's book on DynamoDB and Rick Houlihans YouTube content.
I also wrote a brief thread about this on Twitter: https://twitter.com/thdxr/status/1394903426023272452?s=19