Opener Installation Issue without Intercom / ohne Gegensprechanlage

Hello everyone.

I am new here and just installed my Nuki 4.0 in my 1st floor flat and am quite happy so far. Now i want to install my Opener to be able to open the house door of the apartment building (in germany). It is an old house so there is no intercom. I open the swith and there are 2 cables, like the app says. It says i should connect the blue and purple wire to the 2 cables in the wall. But which to which doesn’t matter? One is red, one is white?!

I am just confused cause the App just says i should connect it with the blue and purple one and make sure it is max 50V and 2A. Am i right that the one luster terminal in the package is not working for that case? I just don‘t know what to do.

For you guys it is most likely a no brainer and i hope you can help me.

Thank you!