I am unable to update to the latest WordPress on account of a outdated PHP.
How can I upgrade PHP to a compatible version ?
An updated version of WordPress is available.
You cannot update because WordPress 5.3 requires PHP version 5.6.20 or higher. You are running version 5.4.45.
While your site is being updated, it will be in maintenance mode. As soon as your updates are complete, your site will return to normal.