When playing against the computer, allow the player to not only choose which side they want to play but also which opening through ECO.
You can try this: go to "TOOLS" -> Board Editor -> select a position from the "Popular openings" list -> Continue from here -> Play with the machine.
Very nice, thank you. Adding ECO numbers would help because, for example, I am looking to practice D56/57 (Lasker's defense) and I can't seem to find it.