RLException: [jetson_nano_bot.launch] is neither a launch file in package [jetson_nano_bot] nor is [

• It probably can't find the file. You can roslaunch it by name-path: roslaunch ~/path/to/file/testbot_description/launch/testbot.launch

https://stackoverflow.com/questions/58698861/how-do-i-deal-with-the-rlexception-error-that-occurred-during-roslaunch