Does Connect Pro 4 work with Performer 3?

Hi, I have VST Connect 4 Pro in Cubase 9 Pro. This is my first time using v4 (although I have used v3 successfully before).
I’m trying to connect with my singer who has VST Connect Performer 3 (Mac & IOS versions). According to the VST Connect info page, this configuration can work. My issue is that I can log into Connect Pro without problem but the singer (who currently doesn’t have a My Steinberg account) seemingly needs to input a numerical key before we can connect. The manual says that both the Engineer & Artist now both need to register My Steinberg accounts to get this to work but if that is the case why does Steinberg’s info page state that v4 can work with v3 (which requires a network key)? Can anyone advise?