NotImplementedError: ROS sensor_msgs not found while reading rosbag

[vishaldolase-honda]

Hi, i am new to ROS2 and pointcloud.
I have Lidar data in rosbag. i want to convert it into kitti dataset format .bin files
i wanted to use pypcd to read the data but its giving following issue

pc = pypcd.PointCloud.from_msg(loc[indx])

File "/home/robot/.local/lib/python3.8/site-packages/pypcd/pypcd.py", line 779, in from_msg
raise NotImplementedError('ROS sensor_msgs not found')
NotImplementedError: ROS sensor_msgs not found

Please provide solution, thank you