It is there a way to send(ex:lower third) to the ATEM switcher?
I mean, no passing through the program signal to the computer, just using the ATEM in the regular way and add the Mimolive graphics inside...
Yes, this is possible. Playout through SDI with key and fill. You need a 2 channel Blackmagic SDI device such as the UltraStudio HD Mini. You can then ingest key and fill into the ATEM.