How to do server side validation of sign up form in django?

Question

I am new to django and I have create a sign up form and its working but when I try to validate password fields to see the if password1 and password2 is matched then I get error. For instance, if my password1=12345678 and password1= TY123456 then I get an error "The view website.views.signUp didn't return an HttpResponse object. It returned None instead". Basically, I just want to dipslay error instead of redirecting to error page. Can anyone help me please? How to do server side validation of signup form.Many Thanks.

view.py

def signUp(request):

    form = UserCreationForm()
    if request.method == 'POST':
        filled_form = UserCreationForm(request.POST)
        if filled_form.is_valid():
            password1 = filled_form.cleaned_data['password1']
            password2 = filled_form.cleaned_data['password2']
            if password1 != password2:
                note='You password does not match'
                return render(request,'signup.html',{'form':form, 'note':note})
            else:
                filled_form.save() 
                return redirect('login')              
    else:
        return render(request,'signup.html',{'form':form})

signup.html

<h1>Sign Up</h1>

<span style="color: red;">{{note}}</span>
<form method="POST">

    {% csrf_token %}

    {{form.as_p}}

  <button type="submit">Sign Up</button>
</form>

urls.py

from django.contrib import admin
from django.urls import path, include
from website.views import home,signUp

urlpatterns = [
    path('admin/', admin.site.urls),
    path('accounts/',include('django.contrib.auth.urls')),
    path('signup/',signUp, name='signup'),
    path('',home,name='home')
]