realsense-ros: Cmake cannot find "realsense2"

I installed SDK2.0 and it works well since I can run realsense-viewer. So installing SDK2.0 should be no problem according to the screen shot below.

I am using Ubuntu18.04 and ROS melodic but could not catkin_make clear and the error message below was shown. What should I do with this issue?

– +++ processing catkin package: ‘realsense2_camera’ – ==> add_subdirectory(realsense-ros/realsense2_camera) – Using these message generators: gencpp;geneus;genlisp;gennodejs;genpy CMake Warning at realsense-ros/realsense2_camera/CMakeLists.txt:44 (find_package): By not providing “Findrealsense2.cmake” in CMAKE_MODULE_PATH this project has asked CMake to find a package configuration file provided by “realsense2”, but CMake did not find one. Could not find a package configuration file provided by “realsense2” (requested version 2.48.0) with any of the following names: realsense2Config.cmake realsense2-config.cmake Add the installation prefix of “realsense2” to CMAKE_PREFIX_PATH or set “realsense2_DIR” to a directory containing one of the above files. If “realsense2” provides a separate development package or SDK, be sure it has been installed. CMake Error at realsense-ros/realsense2_camera/CMakeLists.txt:48 (message): Intel RealSense SDK 2.0 is missing, please install it from https://github.com/IntelRealSense/librealsense/releases – Configuring incomplete, errors occurred! See also “/home/project/catkin_ws/build/CMakeFiles/CMakeOutput.log”. See also “/home/project/catkin_ws/build/CMakeFiles/CMakeError.log”. Invoking “cmake” failed