Frontend Repo - https://github.com/psterckx/tictactoe-frontend
Backend Repo - https://github.com/psterckx/tictactoe-backend
Open this link https://tictactoe.psterckx.be in two separate tabs (you can also open the link on two different devices or ask a friend to play with you).
Click Start game in both tabs. Both clients will establish connections to the backend and request a game. Then the clients will be matched with each other and a game will start.