I was following this link, but at my home the situation is a little bit different:
Should I connect those wires form the wall which are not being used?
Or should I just split wiries form the nuki opener and put first 3 into first terminal and others into second?
This is a custom serbian manufacturer of intercoms Elfon, the board has a mark ELFON PST-2ZIC
You need from the opener wires, - blue and purple for the opening function, yellow and green for the ring functions, red and orange for mic and speaker (have no functions yet), and black is a second gnd. You can let away what you want, just the depending functions are not there then, - so for your question, yes you can let away the green wire (also the yellow then), but you have no ring functions then.