Connecting ardupilot to MAVROS

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I have a question regarding connecting mavros to ardupilot (https://masoudir.github.io/mavros_tut...). I have a jetson nano connected to a pixhawk(in Telem2 port on pixhawk) and also a lidar connected to the same pixhawk(I2C) and want to view the rangefinder(lidar) data on the jetson nano in /mavros/distancesensor/rangefinder/pub(as in https://ardupilot.org/dev/docs/ros-di...) . How would I type the roslaunch line(e.g. roslaunch mavros apm.launch fcu_url:=udp://:14550@) to connect ardupilot and ROS for my case? Hope you can help.... http://wiki.ros.org/mavros#Usage