Our partner seems to require both, a "SID" and a password.
I find no way to configure the SID (which is a three-letter string)
Version in use is 1.0 build 39 from 2019-01-04
Note that this is not the SSID.
Looks like the setup works without a "SID" setting on my side. I still don't know why it is a requested information for setting up the connection.