networking – How do you create a linking service for a turn-based iOS board game?

I want to create a board game that matches players with similar skill levels.

Take for example an iOS application for chess. Log in and the game puts you in competition with someone with a similar elo rank.

But they use a network infrastructure. I have not been able to suggest the type of network architecture to use.

I've tried Google and searched YouTube for solutions to create a multiplayer solution, and I have not found anything special.

The closest thing I know is to simply use the built-in GameKit features offered by Apple.

Otherwise, I have to use some elements called REST, SOAP, Amazon AWS or Unity's UNET multiplayer mapping service. And all is well, but I have not been able to find specific instructions on how to use these services.

What I'm trying to say: there does not seem to be a default solution for multiplayer games in 2018.

What should I use? What can I use? Do I have to stick to the basic features of Game Center?

Should I explore other services or take a few months to create a customized solution?

What is the most effective way to create a multiplayer server for a simple board game between two players?