Run and build this like any Haskell program. You can start entering input as soon as you run the program.
T3 is based on commands like showBoard. There also are commands like addPlayer <username> <mark>, pickSpot <column> <row>, and setBoardSize <width> that modify the state of the board.
While the program will by default take input from stdin and print output to stdout, you can save all your commands to a file game.txt, separated by newlines, and run the program like this:
$ stack exec t3-exe < game.txt > game-output.txt
Have fun!