title: Django - Custom model cannot appear on User model
body: <p>I have created a model in Django v4, and I want to show the information inside the User admin view. After migrating, a new table was created successfully and data is being stored. Here is the code:</p>
  <p>models.py</p>
  <pre><code>from django.db import models
  from django.contrib.auth.models import User
  
  class Profile(models.Model):
      user = models.OneToOneField(
          User,
          on_delete=models.CASCADE
      )
  
      address = models.CharField(
          max_length=20,
          blank=True,
          null=True
      )
  
      def __str__(self):
          return self.user.username
  </code></pre>
  <p>admin.py</p>
  <pre><code>from django.contrib import admin
  from django.contrib.auth.models import User
  from .models import Profile
  
  class ProfileInline(admin.StackedInline):
      model = Profile
      can_delete = False
      verbose_name_plural = 'Extra Information'
  
  @admin.register(ProfileInline)
  class UserAdmin(admin.ModelAdmin):
      inlines = [
          ProfileInline,
      ]
  </code></pre>
  <p>The table that has been created has the following stored:</p>
  <div class="s-table-container">
  <table class="s-table">
  <thead>
  <tr>
  <th style="text-align: left;">id</th>
  <th style="text-align: center;">address</th>
  <th style="text-align: center;">user_id</th>
  </tr>
  </thead>
  <tbody>
  <tr>
  <td style="text-align: left;">3</td>
  <td style="text-align: center;">Test</td>
  <td style="text-align: center;">2</td>
  </tr>
  </tbody>
  </table>
  </div>
  <p>Where the <strong>user_id</strong> column, is a foreign key from the <strong>auth_user</strong> table, which is created automatically (I guess?).</p>
  <p>Now, when I try to run, makemigrations, etc, it shows me the following:</p>
  <p><code>AttributeError: type object 'ProfileInline' has no attribute '_meta'</code></p>
  <p>What is the proper way to have the information appended to the User, as the default sections do?</p>