Before trying any of the teleoperation nodes, check out the and follow all instructions for its usage in this project.
To run the robot_arm_controller.py node which enables the user to teleoperate an XARM6 arm manipulator in the Gazebo Classic and RViz 2 environments, launch the robot_arm_telelop_launch.py launch file with the following command after running colcon_build and sourcing with source install/setup.bash:
ros2 launch xarm_vision robot_arm_telelop_launch.py