The LL library src and include files are in the same directories as HAL libraries. So if your project uses HAL libs, the include paths are already set.
The only thing to add is macro USE_FULL_LL_DRIVER in the C preprocessor definitions.
Depending on how you created the project, the include and library src paths can point to Keil package directory or STM32 CubeMX repository.
The Keil "packs" for STM32 contain complete STM32xxxHAL_Driver libraries, same as in CubeMX repository. But their version numbering is unrelated. To see which ST version it is, look in the Release_Notes.html file in the STM32xxxHAL_Driver subdir of the Keil pack.
For example: The Keil pack STM32F4xx_DFP ver. 2.13.0 has ST libraries version 1.21.0 (23-feb-2108).
Hope this helps.
-- pa
