Next, let's create the template called addarena.html, which will be added to the templates folder inside the application folder. At the top of the HTML file, in the head section, add the CSS, JavaScript, and jQuery libraries:
<!DOCTYPE html><html><head> <title>Arena Map</title> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <link rel="stylesheet" href="https://unpkg.com/leaflet@1.2.0/dist/leaflet.css" /> <script src="https://unpkg.com/leaflet@1.2.0/dist/leaflet.js"></script> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script></head>
