보통 <body> 태그 끝에
<script src="JS파일이름을 여기에"><script><script src="app.js"><script>
을 입력해준다.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<link rel="stylesheet" href="style.css" />
<title>Momentum</title>
</head>
<body>
<script src="app.js"></script>
</body>
</html>
