Django CreateView doesn call the success url - python-3.x

Question

My CreateView doesn't call the success url, i've also tried using get_success_url function but still gives the same result, it just returns the form sending the request.
It actually creates the objects in the data base and prints out the entered value, but it never goes to the success url.
This is what i've got
MODELS.PY
from django.db import models
from ckeditor.fields import RichTextField
from django_random_id_model import RandomIDModel
DELIVERED_OPTIONS = (
("false", "Not Delivered"),
("true", "Delivered"),
)
# Create your models here.
class Order(models.Model):
name = models.CharField(max_length=200)
email = models.CharField(max_length=200)
address = models.CharField(max_length=200)
phone = models.CharField(max_length=200)
measurements = RichTextField(default='')
delivered = models.CharField(
max_length=200, choices=DELIVERED_OPTIONS, default="false")
FORMS.PY
from django import forms
from ckeditor.widgets import CKEditorWidget
from .models import Order
class DeliveryForm(forms.ModelForm):
class Meta:
model = Order
exclude = ["id"]
fields = ['name', 'email', 'address', 'phone', 'measurements']
name = forms.CharField(label="Enter your full Name", min_length=5, widget=forms.TextInput(
attrs={'placeholder': 'Full name please', 'class': 'form-control'}))
email = forms.CharField(label="Enter your Email address", widget=forms.EmailInput(
attrs={'placeholder': 'Enter a valid email address', 'class': 'form-control'}))
address = forms.CharField(label="Enter Your delivery address", widget=forms.TextInput(
attrs={'placeholder': 'Delivery address', 'class': 'form-control'}))
phone = forms.CharField(label="Enter your phone number", widget=forms.NumberInput(
attrs={'placeholder': 'A valid phone number', 'class': 'form-control'}))
measurements = forms.CharField(widget=CKEditorWidget(
attrs={'class': 'form-control', 'rows': '3'}), required=True)
def send_email(self):
pass
URL.PY
from django.urls import path
from . import views
urlpatterns = [
path('', views.DeliveryFormView.as_view(), name="delivery"),
path('order_completed', views.OrderCompleted, name="order_completed"),
]
VIEWS.PY
from django.shortcuts import render
from django.urls import reverse_lazy, reverse
from delivery.form import DeliveryForm
from django.views.generic import CreateView
# Create your views here.
class DeliveryFormView(CreateView):
# context = {
# "route": "Contact",
# "route_text": "Reach out to us for enquiries and suggestions and complaints"
# }
form_class = DeliveryForm
template_name = 'delivery/delivery_form.html'
success_url = reverse_lazy("order_completed")
def form_valid(self, form):
print(form.cleaned_data)
self.send_mail(form.cleaned_data)
return super(DeliveryFormView, self).form_valid(form)
def send_mail(self, valid_data):
print(valid_data)
def OrderCompleted(request):
print("Order Completed")
# Generate an order number
# save the order number to the database along with
# order name, ordered items, total price
return render(request, "delivery/success.html")