<app.py 현재 코드입니다.>

from flask import Flask, render_template, request, jsonify
app = Flask(__name__)

from pymongo import MongoClient
import certifi

ca = certifi.where()
client = MongoClient('mongodb+srv://test:sparta@cluster0.1qvftgf.mongodb.net/Cluster0?retryWrites=true&w=majority', tlsCAFile=ca)
db = client.dbsparta

@app.route('/')
def home():
    return render_template('index_html')

@app.route("/homework", methods=["POST"])
def homework_post():
    n_name_receive = request.form["n_name_give"]
    comment_receive = request.form["comment_give"]

    doc = {
        'n_name':n_name_receive,
        'comment':comment_receive
    }

    db.homework.insert_one(doc)
    return jsonify({'msg':'등록 완료!'})

@app.route("/homework", methods=["GET"])
def homework_get():
    return jsonify({'msg':'GET 연결 완료!'})

if __name__ == '__main__':
    app.run('0.0.0.0', port=5000, debug=True)

<결과 코드 입니다.>

/Users/jayden/Desktop/Sparta/projects/homework/venv/bin/python /Users/jayden/Desktop/Sparta/projects/homework/app.py 
WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on all addresses (0.0.0.0)
 * Running on http://127.0.0.1:5000
 * Running on http://192.168.219.127:5000
Press CTRL+C to quit
 * Restarting with stat
 * Serving Flask app 'app'
 * Debug mode: on
 * Debugger is active!
 * Debugger PIN: 140-332-209
127.0.0.1 - - [15/Aug/2022 20:28:25] "GET / HTTP/1.1" 500 -
Traceback (most recent call last):
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/flask/app.py", line 2548, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/flask/app.py", line 2528, in wsgi_app
    response = self.handle_exception(e)
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/flask/app.py", line 2525, in wsgi_app
    response = self.full_dispatch_request()
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/flask/app.py", line 1822, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/flask/app.py", line 1820, in full_dispatch_request
    rv = self.dispatch_request()
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/flask/app.py", line 1796, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
  File "/Users/jayden/Desktop/Sparta/projects/homework/app.py", line 13, in home
    return render_template('index_html')
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/flask/templating.py", line 146, in render_template
    template = app.jinja_env.get_or_select_template(template_name_or_list)
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/jinja2/environment.py", line 1081, in get_or_select_template
    return self.get_template(template_name_or_list, parent, globals)
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/jinja2/environment.py", line 1010, in get_template
    return self._load_template(name, globals)
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/jinja2/environment.py", line 969, in _load_template
    template = self.loader.load(self, name, self.make_globals(globals))
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/jinja2/loaders.py", line 126, in load
    source, filename, uptodate = self.get_source(environment, name)
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/flask/templating.py", line 62, in get_source
    return self._get_source_fast(environment, template)
  File "/Users/jayden/Desktop/Sparta/projects/homework/venv/lib/python3.10/site-packages/flask/templating.py", line 98, in _get_source_fast
    raise TemplateNotFound(template)
jinja2.exceptions.TemplateNotFound: index_html
127.0.0.1 - - [15/Aug/2022 20:28:25] "GET /?__debugger__=yes&cmd=resource&f=style.css HTTP/1.1" 304 -
127.0.0.1 - - [15/Aug/2022 20:28:25] "GET /?__debugger__=yes&cmd=resource&f=debugger.js HTTP/1.1" 304 -
127.0.0.1 - - [15/Aug/2022 20:28:25] "GET /?__debugger__=yes&cmd=resource&f=console.png HTTP/1.1" 304 -
127.0.0.1 - - [15/Aug/2022 20:28:25] "GET /?__debugger__=yes&cmd=resource&f=console.png HTTP/1.1" 304 -