I hadn't even thought about it. because I used to passcode not Face ID or Touch ID. As you said, I think I'll need some example code for authenticating with Face ID and Touch ID, as well as a password.

I am creating simple app managing credential information. so I thought someone needs authenticate for using app. and I used to passcode not Face ID or Touch ID. so I wanted to find some example code for authenticate via passcode. Workflow is simple. a user set preference for using authenticate. then whenever app activates, a user should authenticate for using app.