<filename>server/users/admin.py
from django.contrib import admin
from django.contrib.auth.admin import UserAdmin as BaseUserAdmin
from django.contrib.auth.models import User

from users.models import Employee


class EmployeeInline(admin.StackedInline):
    model = Employee
    can_delete = False
    verbose_name_plural = 'employee'


class UserAdmin(BaseUserAdmin):
    inlines = (EmployeeInline,)


admin.site.unregister(User)
admin.site.register(User, UserAdmin)
<filename>server/users/admin.py
from django.contrib import admin
from django.contrib.auth.admin import UserAdmin as BaseUserAdmin
from django.contrib.auth.models import User

from users.models import Employee


class EmployeeInline(admin.StackedInline):
    model = Employee
    can_delete = False
    verbose_name_plural = 'employee'


class UserAdmin(BaseUserAdmin):
    inlines = (EmployeeInline,)


admin.site.unregister(User)
admin.site.register(User, UserAdmin)