How to add more details to the UserInfo when calling /v2/userInfo REST API?

Support
#1

Hello, I would like to add more details to the UserInfo when calling the REST API /v2/userInfo from an external app and to be used there. How can I do it?

{
    "id": "12345678",
    "login": "user1",
    "name": "User 1",
    "firstName": null,
    "middleName": null,
    "lastName": null,
    "position": null,
    "email": null,
    "timeZone": null,
    "language": null,
    "_instanceName": "User 1 [user1]",
    "locale": "en",
-------additional details--------
    "email": "user1@abc.com"
    .
    .
}