Any Verfication Code(like a password)

[Problem/Question]
// Detailed description of issue.

Hello!

I am building an app using your call solution. I am considering using your group call for my service since call room should be created first and then the other use followed coming in. Thus, I need a verification code logic for entering the group call. It might be simple password such as 1234 some like that.

Is there any verification code to enter group call(not a roomid) to use or should I make it myself?

I have read your docs for Video Call SDK and also checked
sendbird/quickstart-calls-groupcall-ios (github.com) out.