Could not find a package configuration file provided by “pcl_ros“ with any of the following names:

Could not find a package configuration file provided by “pcl_ros” with any of the following names:

CMake Error at /opt/ros/melodic/share/catkin/cmake/catkinConfig.cmake:83 (find_package):
  Could not find a package configuration file provided by "pcl_ros" with any
  of the following names:

    pcl_rosConfig.cmake
    pcl_ros-config.cmake

  Add the installation prefix of "pcl_ros" to CMAKE_PREFIX_PATH or set
  "pcl_ros_DIR" to a directory containing one of the above files.  If
  "pcl_ros" provides a separate development package or SDK, be sure it has
  been installed.

sudo apt-get install ros-melodic-pcl-ros