Exemplo - Estendendo o UserCreationForm do Django.

forms.py

#forms.py

from django import forms
from django.contrib.auth.models import User
from django.contrib.auth.forms  import UserCreationForm
from .models import Profile

class UserRegisterForm(UserCreationForm):
    email = forms.EmailField()
    
    class Meta:
        model = User
        fields = ['username', 'email', 'password1', 'password2']


class UserUpdateForm(forms.ModelForm):
    email = forms.EmailField()
    
    class Meta:
        model = User
        fields = ['username', 'email']
        

class ProfileUpdateForm(forms.ModelForm):
    class Meta:
        model = Profile
        fields = ['image']

password1 = password
password2 = confirmação do password