NAV2 help needed

Hey everyone,
I am trying to simulate turtlebot3 with unity using the GitHub - Unity-Technologies/Robotics-Nav2-SLAM-Example: An example project which contains the Unity components necessary to complete Navigation2's SLAM tutorial with a Turtlebot3, using a custom Unity environment in place of Gazebo. repo
I am not facing any issues but the repo did not mention about how we can launch the nav2 bringup
could someone help me out with the steps(the command) to perform nav2.