Hemant Vishwakarma: Insert Dash Barchart into a HTML page via Flask Framework

I'm trying to insert a barchart into my website which has been written in Flask. Here is what my app.py looks like:

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

@app.route("/")
def index():
    return render_template('index.html', title="Mainpage")

if __name__=='__main__':
    app.run(debug=True)

Here is what my barchart looks like (chart.py):

# -*- coding: utf-8 -*-
import dash
import dash_core_components as dcc
import dash_html_components as html

external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

app = dash.Dash(__name__, external_stylesheets=external_stylesheets)

app.layout = html.Div(children=[

    dcc.Graph(
        id='example-graph',
        figure={
            'data': [
                {'x': [1, 2, 3], 'y': [4, 1, 2], 'type': 'bar', 'name': 'SF'},
                {'x': [1, 2, 3], 'y': [2, 4, 5], 'type': 'bar', 'name': u'Montréal'},
            ],
        }
    )
])

if __name__ == '__main__':
    app.run_server(debug=True)

And here is what my html looks like (index.html):

<!DOCTYPE html>
<html lang="en">
<title>W3.CSS Template</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://www.w3schools.com/w3css/4/w3.css">
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Lato">
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Montserrat">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<style>
body,h1,h2,h3,h4,h5,h6 {font-family: "Lato", sans-serif}
.w3-bar,h1,button {font-family: "Montserrat", sans-serif}
.fa-anchor,.fa-coffee {font-size:200px}
</style>
<body>

<!-- Navbar -->
<div class="w3-top">
  <div class="w3-bar w3-red w3-card w3-left-align w3-large">
    <a class="w3-bar-item w3-button w3-hide-medium w3-hide-large w3-right w3-padding-large w3-hover-white w3-large w3-red" href="javascript:void(0);" onclick="myFunction()" title="Toggle Navigation Menu"><i class="fa fa-bars"></i></a>
    <a href="#" class="w3-bar-item w3-button w3-padding-large w3-white">Home</a>
    <a href="#" class="w3-bar-item w3-button w3-hide-small w3-padding-large w3-hover-white">Link 1</a>
    <a href="#" class="w3-bar-item w3-button w3-hide-small w3-padding-large w3-hover-white">Link 2</a>
    <a href="#" class="w3-bar-item w3-button w3-hide-small w3-padding-large w3-hover-white">Link 3</a>
    <a href="#" class="w3-bar-item w3-button w3-hide-small w3-padding-large w3-hover-white">Link 4</a>
  </div>

  <!-- Navbar on small screens -->
  <div id="navDemo" class="w3-bar-block w3-white w3-hide w3-hide-large w3-hide-medium w3-large">
    <a href="#" class="w3-bar-item w3-button w3-padding-large">Link 1</a>
    <a href="#" class="w3-bar-item w3-button w3-padding-large">Link 2</a>
    <a href="#" class="w3-bar-item w3-button w3-padding-large">Link 3</a>
    <a href="#" class="w3-bar-item w3-button w3-padding-large">Link 4</a>
  </div>
</div>

<!-- Header -->
<header class="w3-container w3-red w3-center" style="padding:128px 16px">
  <h1 class="w3-margin w3-jumbo">START PAGE</h1>
  <p class="w3-xlarge">Template by w3.css</p>
  <button class="w3-button w3-black w3-padding-large w3-large w3-margin-top">Get Started</button>
</header>

<!-- First Grid -->
<div class="w3-row-padding w3-padding-64 w3-container">
  <div class="w3-content">
    <div class="w3-twothird">
      <h1>Bar Chart</h1>

        <h2>Insert bar chart here</h2>

  </div>
</div>

</body>
</html>

I want a site where I can embed dash or seaborn or plotly or possibly d3 charts onto one page. With the dash chart, I'm hoping to make a site that looks something like this: