Как исправить ошибку Internal Server Error?

Question

Dmitry @Atroshchenko-Dima

Python, postgres

Flask

Как исправить ошибку Internal Server Error?

Пытаюсь API запросом вытащить таблицу из postgresql на html страничку. Делаю это впервые.
При запуске приложения python app.py вылазит данная ошибка

Internal Server Error
The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.

В visual studio code после запуска приложения вижу это

* Serving Flask app 'app'
 * Debug mode: off
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on http://127.0.0.1:5000
Press CTRL+C to quit
[2023-03-31 11:16:31,726] ERROR in app: Exception on / [GET]
Traceback (most recent call last):
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\app.py", line 2528, in wsgi_app
    response = self.full_dispatch_request()
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\app.py", line 1825, in full_dispatch_request
    rv = self.handle_user_exception(e)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\app.py", line 1823, in full_dispatch_request
    rv = self.dispatch_request()
         ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\app.py", line 1799, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\Desktop\toplivobd\app.py", line 22, in index
    return render_template("index.html", rows=rows)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\templating.py", line 146, in render_template
    template = app.jinja_env.get_or_select_template(template_name_or_list)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\jinja2\environment.py", line 1081, in get_or_select_template
    return self.get_template(template_name_or_list, parent, globals)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\jinja2\environment.py", line 1010, in get_template
    return self._load_template(name, globals)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\jinja2\environment.py", line 969, in _load_template
    template = self.loader.load(self, name, self.make_globals(globals))
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\jinja2\loaders.py", line 126, in load
    source, filename, uptodate = self.get_source(environment, name)
                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\templating.py", line 62, in get_source
    return self._get_source_fast(environment, template)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\templating.py", line 98, in _get_source_fast
    raise TemplateNotFound(template)
jinja2.exceptions.TemplateNotFound: index.html
127.0.0.1 - - [31/Mar/2023 11:16:31] "GET / HTTP/1.1" 500 -
[2023-03-31 11:18:30,537] ERROR in app: Exception on / [GET]
Traceback (most recent call last):
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\app.py", line 2528, in wsgi_app
    response = self.full_dispatch_request()
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\app.py", line 1825, in full_dispatch_request
    rv = self.handle_user_exception(e)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\app.py", line 1823, in full_dispatch_request
    rv = self.dispatch_request()
         ^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\app.py", line 1799, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\Desktop\toplivobd\app.py", line 22, in index
    return render_template("index.html", rows=rows)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\templating.py", line 146, in render_template
    template = app.jinja_env.get_or_select_template(template_name_or_list)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\jinja2\environment.py", line 1081, in get_or_select_template
    return self.get_template(template_name_or_list, parent, globals)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\jinja2\environment.py", line 1010, in get_template
    return self._load_template(name, globals)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\jinja2\environment.py", line 969, in _load_template
    template = self.loader.load(self, name, self.make_globals(globals))
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\jinja2\loaders.py", line 126, in load
    source, filename, uptodate = self.get_source(environment, name)
                                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\templating.py", line 62, in get_source
    return self._get_source_fast(environment, template)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\antrodmi\AppData\Local\Programs\Python\Python311\Lib\site-packages\flask\templating.py", line 98, in _get_source_fast
    raise TemplateNotFound(template)
jinja2.exceptions.TemplateNotFound: index.html
127.0.0.1 - - [31/Mar/2023 11:18:30] "GET / HTTP/1.1" 500 -

В папке только два файла:
app.py

from flask import Flask, render_template
import psycopg2

app = Flask(__name__)

params = {
    "host": "localhost",
    "port": 5432,
    "user": "postgres",
    "password": "postgres",
    "database": "postgres"
}

conn = psycopg2.connect(**params)

@app.route("/")
def index():
    cur = conn.cursor()
    cur.execute("SELECT * FROM toplivo;")
    rows = cur.fetchall()
    cur.close
    return render_template("index.html", rows=rows)
if __name__ == "__main__":
    app.run()

и index.html

<!DOCTYPE html>
<html>
<head>
    <title>Топливо</title>
</head>
<body>
    <table>
        <thead>
            <tr>
                <th>month</th>
                <th>counterparty</th>
                <th>type_obligations</th>
                <th>treaty</th>
                <th>number_invoices</th>
                <th>date</th>
                <th>station</th>
                <th>k</th>
                <th>quantity</th>
                <th>cost_without_nds_rub</th>
                <th>price_rub_thousand_m3</th>
                <th>supplier_calorie</th>
                <th>calorie_power_plant</th>
                <th>Quantity_tut</th>
                <th>price_rub_tut</th>
                <th>supplier_calorie_weighted_average</th>
                <th>avarege_calorie_station</th>
            </tr>
        </thead>
        <tbody>
            {% for row in rows %}
            <tr>
                <td>{{ row[0] }}</td>
                <td>{{ row[1] }}</td>
                <td>{{ row[2] }}</td>
                <td>{{ row[3] }}</td>
                <td>{{ row[4] }}</td>
                <td>{{ row[5] }}</td>
                <td>{{ row[6] }}</td>
                <td>{{ row[7] }}</td>
                <td>{{ row[8] }}</td>
                <td>{{ row[9] }}</td>
                <td>{{ row[10] }}</td>
                <td>{{ row[11] }}</td>
                <td>{{ row[12] }}</td>
                <td>{{ row[13] }}</td>
                <td>{{ row[14] }}</td>
                <td>{{ row[15] }}</td>
                <td>{{ row[16] }}</td>
            </tr>
            {% endfor %}
        </tbody>
    </table>
</body>
</html>

Подскажите, пожалуйста, в чем моя ошибка?