I have made this type in typescript and I want to use it to construct objects but I am getting confused and the only way have been able to make an object is by passing it through as a parameter of a function I am not really too sure how to make a constructor or my type.

export type UserIdType = {
  userId: string;
  email?: string;
  title?: string;}

The only way I have been able to make an object is like this

const PersonalDetails = ({navigation}: Props,userId:UserIdType) => {

  userId.userId

what is the correct way for me to make an object using a custom type I just want to make a default object that just has default values of each of the types in the type.