Example for FbTcpServer_Multiconnect_base

I’m trying to configure FbTcpServer_Multiconnect_base in order to receive several connections at the same time. Please help me with an example. How can I use this Fb in ST language.
I couldn’t figure it out right away from the documentation.

I connected FbTcpServerMulticonnect but I get an error whether Fb is enabled or not. I am attaching a screenshot.

Tell me what does unknown error mean?

I tried many different options but the connection could not be established. I suspect that the fb description is incorrect. The screenshot below shows that there is some kind of address. But there is no address on FB itself.