KCodecs
Text encoding.
KCodecs provide a collection of methods to manipulate strings using various encodings.
It can automatically determine the charset of a string, translate XML entities, validate email addresses, and find encodings by name in a more tolerant way than QTextCodec (useful e.g. for data coming from the Internet).
Using the Module
Using a Qt module's C++ API requires linking against the module library, either directly or through other dependencies. Several build tools have dedicated support for this, including CMake and qmake.
Building with CMake
Use the find_package() command to locate the needed module component in the Qt6 package:
find_package(Qt6 REQUIRED COMPONENTS KF6)
target_link_libraries(mytarget PRIVATE Qt6::KF6)
For more details, see the Build with CMake overview.