Electronic Chess Board Integration

How do electronic chess boards from DGT, Millennium and others integrate with chess.com?

The site wrote code to support the DGT software as I understand it.

https://support.chess.com/article/1257-how-can-i-play-with-a-dgt-board

Some manufacturers have an agreement with the site to access the private API (such as how Square-Off works)

Thanks for confirmation and quick response. I was looking at that post as well.

Please: can you build a (haulOgram) in a 3 yard cube 
that would be 9x9x9 cubic feet 
that would be 12" per foot that is 27 cubic feet per Yard 
so two people could play from (above & across from 
each other) on the level with the best view of "The game"