Please help connecting RFlink to RPI 3

I try to connect my RFlink to an RPI 3.

I spent several hours trying lots of options but still no luvk
To the default configuration.yaml I addedd these three lines:
port: /dev/ttyACM0
wait_for_ack: False

But nothing happens.
I expected to show up a switch when I press a kaku (433Mhz device)

So if someone would share an example of the code to connect an RFlink i would be very gratefull