You know that ros melodic replaced ros-kinetic.
Python3 replaced python2.
How do Robotis-Op3 work with ros melodic and python3? There are steps to work it.
Thank you for your inquiry.
OP3 is currently running on ROS1 Kinetic and upgrading to Melodic or Noetic may be difficult at this point due to the dependency of 3rd party packages that are not supported in Melodic or Noetic.