Hi Dieter,
you will need the LCIA method that fits to the EPD, and that is provided with our EN15804 add-on (but maybe also otherwise on Nexus). Maybe it is also otherwise available on Nexus but I did not check now. I would anyhow recommend to use the add-on if you are creating an EPD for EN15804 as this will provide the required indicators, as far as possible. When you "just" use a generic database, you will see no contributions for these inventory indicators, from the database.
Best wishes,
Andreas