Add this snippet to your theme’s functions.php file to use.
Be sure to change the value of $redirect_url from https://mjslawson.com to the URL users should be redirected to.
Create a directory: ‘maintenance’, and within place a simple HTML file: index.html. Landing pages should include a background image, logo and message maybe something like: “Scheduled Maintenance. Check back soon.” Throw in a couple social media links, a phone number if it’s appropriate and you’re good to go!
My maintenance page is available at: https://mjslawson.com/maintenance/
I’ve also used the code snippet on my old website to redirect to the new one, unless I’m logged in.