I have tried multiple browsers and using your example simply does not produce any logs on Loggly.
I can see the HTTP request in my browser tools (on Safari, Chrome, and Firefox) all make a successful request and get a 200 response.
What is wrong with the following page:
<html lang="en">
<head>
<meta charset="utf-8">
<title>Testapp</title>
<base href="/">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="icon" type="image/x-icon" href="favicon.ico">
<script type="text/javascript" src="">cloudfront.loggly.com/.../script>
<script>
var _LTracker = _LTracker || [];
_LTracker.push({
'logglyKey': 'I REMOVED MY KEY',
'sendConsoleErrors': false,
'tag': 'javascript-logs'
});
</script>
</head>
<body onload="javascript: _LTracker.push('This is a test from an HTML page');">
Hello this is a test.
</body>
</html>