<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<script
src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
</head>
<body>
<button type="button" id="subscribe">Следить за изменениями</button>
</body>
</html>
<script src="https://www.gstatic.com/firebasejs/5.4.1/firebase.js"></script>
<script type="text/javascript" src="/firebase_subscribe.js"></script>$_JSON = @json_decode(file_get_contents('php://input'));<body style="background-color:<?php echo $bgcolor; ?>">