input: 
  def create_user_model(app_name: str, fields: List[str]) -> str:
      """ Create a Django model for a user with specified fields in a given app.
      The fields should include 'name', 'address', and 'email'.
      >>> create_user_model('myapp', ['name', 'address', 'email'])
      'python manage.py makemigrations'
      """
  
output:     model_code = f"""
  from django.db import models
  
  class User(models.Model):
      name = models.CharField(max_length=255)
      address = models.CharField(max_length=255)
      email = models.EmailField()
  """
      for field in fields:
          if field not in ['name', 'address', 'email']:
              model_code += f"    {field} = models.CharField(max_length=255)\n"
      
      model_code += f"""
      class Meta:
          app_label = '{app_name}'
  """
      return 'python manage.py makemigrations'