localhost:5000과 연결이 안됩니다..

작성한 코드 및 에러 메세지

<app,py 부분>

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

from pymongo import MongoClient
client = MongoClient('mongodb+srv://test:sparta@cluster0.98rz0ep.mongodb.net/Cluster0?retryWrites=true&w=majority')
db = client.dbsparta

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

@app.route("/mars", methods=["POST"])
def web_mars_post():
    name_receive = request.form['name_give']
    address_receive = request.form['address_give']
    size_receive = request.form['size_give']
    doc = {
        'name' : name_receive,
        'address' : address_receive,
        'size' : size_receive
    }
    db.mars.insert_one(doc)

    return jsonify({'msg': '주문 완료!'})

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

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



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<index.html 부분>

<script>
    $(document).ready(function () {
        show_order();
    });
    function show_order() {
        $.ajax({
            type: 'GET',
            url: '/mars',
            data: {},
            success: function (response) {
                alert(response['msg'])
            }
        });
    }
    function save_order() {
        let name =$('#name').val()
        let address =$('#address').val()
        let size =$('#size').val()

        $.ajax({
            type: 'POST',
            url: '/mars',
            data: {name_give:'name', address_give:'address', size_give:'size'},
            success: function (response) {
                alert(response['msg'])
                window.location.reload()
            }
        });
    }