Okay, I figured it out!
When you choose Generic AES67 input, you need to type your subrange and your channel. Subrange is the second octet of the multicast address of your AES67 stream. Channel is the fourth (last) octet of the multicast address of your AES67 stream.
Then, sound should just start playing. There isn't any other indication of success.
And, the discovery stuff doesn't work. There isn't a list generated under "Device" even though Ravenna and AES67 streams are announced on the network.
So, if you don't know your AES67 stream address[es], open Wireshark and take a look from there
Short guide: multicast address of your AES67 stream: 239.<subrange>.0.<channel>