Unable to try the demo

When I insert “roslaunch bb_8_teleop keyboard_teleop.launch” in cell 1
I receive this error
[keyboard_teleop.launch] is neither a launch file in package [bb_8_teleop] nor is [bb_8_teleop] a launch file name
The traceback for the exception was written to the log file

I can’t solve this error

Hello @LauYieHang,

What course is this error from? I don’t think it’s related to the Navigation course. Could you please specify which course are you getting this error from?