Setting CMake curl variables for building curlpp

Question

I use C++, curl 7.64, CMake 3.19.3, curlpp 0.8.1, Windows 7 OS. I cannot build curlpp out-of-the-box. CURL_FOUND is set to true, but CURL_INCLUDE_DIRS and CURL_LIBRARIES are empty (AFAIK, CMake module delegates variables filling to curl CMake module).

I've set CURL_INCLUDE_DIRS manually, but setting CURL_LIBRARIES="debug "path_to_debug" optimized "path_to_release"" fails. So, I've got linker errors.

BTW, why do some curl-consuming CMakeLists.txt files use ${CURL_LIBRARIES} and the other ones use CURL::libcurl for feeding target_link_libraries?