https://github.com/Markpdf/sdk-cpp/releases

include(FetchContent)
FetchContent_Declare(
  markpdf-cpp
  URL https://github.com/Markpdf/sdk-cpp/archive/refs/tags/v0.1.0.tar.gz
)
FetchContent_MakeAvailable(markpdf-cpp)

target_link_libraries(your_app PRIVATE markpdf::markpdf)

MARKPDF_API_KEY=YOUR_API_KEY

#include <markpdf/client.hpp>

int main() {
    markpdf::Client client;
}

https://api.markpdf.tech