Your system listing is missing the crucial central component, the Roon core, since your MPAC-III is “only” a network player/streamer (click the link to go to Roon’s knowledge base and read up on Roon’s system concept).
Marin_Weigel is correct. We would have made sure you (@Remus_Preda) had the right pieces prior to selling you this unit had you purchased it directly from us. (@MusicaPristina)
You have a few options:
Run Roon Core on a desktop/laptop pc on your network, connected via ethernet
Build yourself a ROCK
Buy a Roon Nucleus
probably other options exist as well
Let’s discuss this offline… I’ll reach out to you today.