配置apache重定向non-www ->www

By default, Apache doesn’t allow the use of .htaccess file, so the steps will be a little different:

1. Enable mod_rewrite by running the following command:
   $ sudo a2enmod rewrite
   Then, restart the Apache web server:
   $ sudo systemctl restart apache2
2. Enable .htaccess with the command:
   $ sudo vi /etc/apache2/sites-available/000-default.conf
   Add the following code before the <VirtualHost> line:
   <Directory /var/www/html>
   Options Indexes FollowSymLinks MultiViews
   AllowOverride All
   Require all granted
   </Directory>
   Then, restart Apache.
3. To create the .htaccess file, enter the command:
   $ sudo vi /var/www/html/.htaccess
4. Add the following lines to the file:
   RewriteEngine on
   RewriteCond %{HTTP_HOST} ^yourdomain.com [NC]
   RewriteRule ^(.*)$ http://www.yourdomain.com/$1 [L,R=301]
5. Restart the Apache server.

All site visitors using the non-www URL should now be redirected to the www version.

Source: https://www.hostinger.com/tutorials/cpanel/how-to-redirect-non-www-urls-to-www#Apache