There are plenty of maintenance extensions that you can use for your flarum active site. E.g https://discuss.flarum.org/d/23930-maintenance-mode
The main purpose of this resource i am sharing is what will happen if you decide to completely delete all your system files and start a fresh? While you are at the backend you won't like your visitors to see 404 error.
You can redirect all traffic to the maintenance page. Does this also mean including you? Urg, no worries.. On this resource, you can put the IP address that you want to see the 404 page.
Inside your root, create a page by name maintenance.php insert below code
Re-edit your Favicon url, Google Analytics, and mailto: then hit Save.
<!DOCTYPE html>
<html>
<head>
<title>Maintenance</title>
<link rel="shortcut icon" href="/favicon.png">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<!-- Global site tag (gtag.js) - Google Analytics -->
<script async src="https://www.googletagmanager.com/gtag/js?id=UA-XXX"></script>
<script>
window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}
gtag('js', new Date());
gtag('config', 'UA-XXX');
</script>
<style>
.center {
text-align: center;
border: 1px solid #d1e0e0;
}
</style>
</head>
<body>
<div>
<body bgcolor="#f6f6f6">
<center><img src="https://i1.wp.com/mobility-work.com/wp-content/uploads/2021/02/pricing-img-1-e1612705874994.png" alt="maintenance" width="100%" height="100%"></center>
<div class="center">
<p>Sorry for the inconvenience but we’re performing some maintenance at the moment. </p> <p>If you need to you can always <a href="mailto:XXX">contact us</a>, otherwise we’ll be back online shortly!</p>
<p>— Team</p>
<br>
</body>
</html>
Create .htaccess file and put
# Redirect the all users to /maintenance.php, except the ones from the specified IP address.
RewriteEngine On
RewriteCond %{REMOTE_ADDR} !^10.10.10.10
RewriteCond %{REQUEST_URI} !^/maintenance/(.)*$ [NC]
RewriteRule ^(.*)$ /maintenance.php [R=302,L]
Change 10.10.10.10 above to your public IP so only you won't be redirected to /maintenance.php
How do I get my ip? Google search: My ip address
Thats it! Enjoy 🎉