Me and my unity developer friend starting new project of poker game in unity(win,mac,android,ios only, web is not priority).

We did some home work for how we can make game engine(game server) for this project and we finally come up with 2 names mostly. NODE.JS and SOCKET.IO + UNITY(frontend client).

I already started learning node.js from basic and did some learning progress in that too. but I am still new for node.

So I am really confuse about how we can connect our game server with our client/s.
Can I make API or WebServices or is there any other method for node to contact unity clients?

I need someone who can guide me for this project with step by step or give me direction in details to make this project complete.

Please Direct me.

this is invite link to join me: https://discord.gg/EdZa4r