I want to define a type for the following data structure

[
  {
   type:'email',
   email:'test@gmai.com'
  },
  {
   type:'username',
   username:'user@123'
  },
  {
   type:'ssoId',
   ssoId:'client@123'
  }
]

As we can see the other keys in the object are based on the type. What is the best way to define type for such structures.

I was thinking of the following

interface Email{
    type:'email',
    email: string;
}

interface UserName{
    type:'username',
    username: string;
}

interface SSOId{
    type:'ssoId',
    ssoId: string;
}

type FinalType=Email|UserName|SSOId

Is this the best way to define FinalType? I want to use this interface in other places too.