multiplayer chess game, board data sync question

Hello,

I am making a multiplayer chess game. I would like to ask what is the best way to share the board data? For example I have a 2d array of tile prefab objects that I am spawning the pieces on. My problem is that I have 2 separate local instances of this tile array.

I would like to ask what would be the best approach for that case? should I create another 2d array of strings (ids) for example and retain both in parallel? or there is a better approach? Having 2 different arrays feels a bit wrong.

Thanks