I see vMix 23 UI and let me ask: How I can send "streamid" in caller mode ?

SRT supports "streamid" (it very seems on "stream key" for rtmp) for access control.
https://github.com/Haivi...er/docs/AccessControl.md

For example FFmpeg supports it for caller:

ffmpeg ...... -I srt://192.168.1.210:9001?streamid=myStream123

So server can listen one port for many clients and do routing by "streamid".

// I known we can use "passphrase" for imitate "accesscontorl" but it's for encryption and means overhead.