如何在Golang的另一个包中将新字段添加到现有类型中

I have a custom AUTH package and there i have USER STRUCT.

So i want to import the auth package in my go project and override the struct or add new fields to the struct without modifying the package code.

package auth
type User struct {
    gorm.Model
    UserEmail string
    UserPass  string
}

Now i have main.go

package main

import "auth"

// WANT TO OVERRIDE OR EXTEND THE USER STRUCT
auth.User = {
    UserAge string
}

function main() {
}    

you can define a new type like this:

type NewUser struct {
  auth.User
  UserAge string
}

So i want to import the auth package in my go project and override the struct or add new fields to the struct without modifying the package code.

You simply cannot do this in Go. You have to redesign.