DjangoでNoReverseMatchエラーが出てしまいます

前提・実現したいこと

https://django.kurodigi.com/
こちらのサイトを参考にdjangoで掲示板サイトを作成したところ、トップページから投稿をするボタンをクリックしたらエラーメッセージが発生してしまいました。

発生している問題・エラーメッセージ

NoReverseMatch at /thread/create_topic/
Reverse for 'create_topic.html' not found. 'create_topic.html' is not a valid view function or pattern name.

該当のソースコード

urls
1from django.urls import path
2
3from . import views
4
5app_name = "thread"
6
7urlpatterns = [
8    path("create_topic/", views.TopicCreateView.as_view(), name="create_topic"),
9    ]

views
1from django.shortcuts import render, redirect, get_object_or_404
2from django.views.generic import CreateView
3from django.urls import reverse_lazy
4from .forms import TopicCreateForm, TopicModelForm, CommentModelForm
5from .models import Topic, Category, Comment
6
7class TopicCreateView(CreateView):
8    template_name = "thread/create_topic.html"
9    form_class = TopicModelForm
10    model = Topic
11    success_url = reverse_lazy("base:top")
12
13    def form_valid(self, form):
14        ctx = {"form": form}
15        if self.request.POST.get("next", "") == "confirm":
16            return render(self.request, "thread/confirm_topic.html", ctx)
17        if self.request.POST.get("next", "") == "back":
18            return render(self.request, "thread/create_topic.html", ctx)
19        if self.request.POST.get("next", "") == "create":
20            return super().form_valid(form)
21        else:
22            # 正常動作ではここは通らない。エラーページへの遷移でも良い
23            return redirect(reverse_lazy("base:top"))
24
25
26def topic_create(request):
27    template_name = "thread/create_topic.html"
28    ctx = {}
29    if request.method == "GET":
30        ctx["form"] = TopicCreateForm()
31        return render(request, template_name, ctx)
32
33    if request.method == "POST":
34        topic_form = TopicCreateForm(request.POST)
35        if topic_form.is_valid():
36            topic_form.save()
37            return redirect(reverse_lazy("base:top"))
38        else:
39            ctx["form"] = topic_form
40            return render(request, template_name, ctx)
41

forms
1from django import forms
2from .models import Topic, Category, Comment
3
4
5class TopicModelForm(forms.ModelForm):
6    class Meta:
7        model = Topic
8        fields = [
9            "title",
10            "user_name",
11            "category",
12            "message",
13        ]
14        widgets = {
15            "title": forms.TextInput(attrs={"class": "hoge"}),
16            "user_name": forms.TextInput(attrs={"value": "名無し"}),
17        }
18
19    def __init__(self, *args, **kwargs):
20        # kwargs.setdefault('label_suffix', '')
21        super().__init__(*args, **kwargs)
22        self.fields["category"].empty_label = "選択して下さい"
23        self.fields["user_name"].widget.attrs["value"] = "匿名"
24        # self.fields['title'].widget.attrs['class'] = 'huga'
25
26
27class TopicCreateForm(forms.Form):
28    title = forms.CharField(
29        label="タイトル",
30        max_length=255,
31        required=True,
32    )
33    user_name = forms.CharField(
34        label="お名前",
35        max_length=30,
36        required=True,
37        widget=forms.TextInput(attrs={"value": "名無し"}),
38    )
39    category = forms.ModelChoiceField(
40        label="カテゴリー",
41        queryset=Category.objects.all(),
42        required=True,
43        empty_label="選択して下さい",
44    )
45    message = forms.CharField(
46        label="本文",
47        widget=forms.Textarea,
48        required=True,
49    )
50
51    def __init__(self, *args, **kwargs):
52        kwargs.setdefault("label_suffix", "")
53        super().__init__(*args, **kwargs)
54
55
56class CommentModelForm(forms.ModelForm):
57    class Meta:
58        model = Comment
59        fields = [
60            "user_name",
61            "message",
62            # "image",
63        ]
64
65    def __init__(self, *args, **kwargs):
66        kwargs.setdefault("label_suffix", "")
67        super().__init__(*args, **kwargs)
68        self.fields["user_name"].widget.attrs["value"] = "名無し"
69
70    def save_with_topic(self, topic_id, commit=True):
71        comment = self.save(commit=False)
72        comment.topic = Topic.objects.get(id=topic_id)
73        comment.no = Comment.objects.filter(topic_id=topic_id).count() + 1
74        if commit:
75            comment.save()
76        return comment

basehtml
1{% load static %}
2<!DOCTYPE html>
3
4<head>
5    <meta charset="UTF-8">
6    <meta http-equiv="content-language" content="ja">
7    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
8    {% block meta_tag %}{% endblock %}
9    <link href="{% static 'css/semantic.css' %}" rel="stylesheet">
10    {% block css %}{% endblock %}
11    <title>
12        {% block title %}掲示板{% endblock %}
13    </title>
14</head>
15
16<body>
17    <div class="ui stackable inverted menu">
18        <a href="{% url 'base:top' %}" class="header item">
19            掲示板
20        </a>
21        <a href="{% url 'base:about' %}" class="item">
22            このサイトは何？
23        </a>
24        <a class="item" href="{% url 'thread:create_topic' %}">
25            投稿する
26        </a>
27        <div class="right menu">
28            <a class="item">
29                Log in
30            </a>
31            <a class="item">
32                Sign up
33            </a>
34        </div>
35    </div>
36
37    <div class="ui container" style="min-height:100vh;">
38        {% block content %}
39        {% endblock %}
40    </div>
41    <div class="ui inverted stackable footer segment">
42        <div class="ui container center aligned">
43            <div class="ui horizontal inverted small divided link list">
44                <a href="{% url 'base:top' %}" class="item">あ</a>
45                <a href="{% url 'base:terms' %}" class="item">い</a>
46                <a href="{% url 'base:policy' %}" class="item">う</a>
47            </div>
48        </div>
49    </div>
50    <script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
51    <script type="text/javascript" src="{% static 'js/semantic.js' %}"></script>
52    {% block js %}{% endblock %}
53</body>

試したこと

pathを以下のものに変えてみましたが同じエラーが出ます。
path("create_topic/", views.topic_create, name="create_topic"),
path("create_topic/str:url_code/", views.TopicCreateView.as_view(), name="create_topic"),