Before making calls, you need to identify the current user to UserKit. This associates the app session with a specific user account. name and email are both optional. 
UserKit.shared.identify(id: "1", name: "Example User", email: "example@user.com")

​
Best Practices

  1. Do not make your user IDs guessable – they are public facing.
  2. Ensure the id is unique per user.
  3. Do not use the device id for user ids - this will result in multiple user records as the device ids rotate.
Setup done Time to make your first call.