Start the Ubuntu side and then the Windows side.
Open a new terminal and run the following command:
$ roslaunch sigverse_turtlebot2 follower.launch
Start the [Assets/SIGVerse/ExampleScenes/Turtlebot2/Turtlebot2Follower(.unity)] scene with reference to here.
When you press the arrow key after focusing on the Unity screen, the human avatar moves and TurtleBot2 follows the avatar.
* To check the TurtleBot2 camera image on the ROS side, execute the following command.
$ rosrun image_view image_view image:=/camera/rgb/image_raw
If you want to finish, stop the Unity side and then the ROS side.
Unity side(The details may differ from the latest version)
Reference Video