Apache and Networks

Actually, There is no need for setup the VirtualHost in your server.

Multisite have two way for visiting, base on subpath and subdomain.

You choose the subpath, So the server don’t need to do anything. Just make sure your apache server support the rewrite.

then add the .htaccess content as the below. It’s for the sub-path.

RewriteEngine On  
RewriteBase /m/  
RewriteRule ^index\.php$ - [L]  

RewriteRule ^([_0-9a-zA-Z-]+/)?wp-admin$ $1wp-admin/ [R=301,L]  

RewriteCond %{REQUEST_FILENAME} -f [OR]  
RewriteCond %{REQUEST_FILENAME} -d  
RewriteRule ^ - [L]  
RewriteRule ^([_0-9a-zA-Z-]+/)?(wp-(content|admin|includes).*) $2 [L]  
RewriteRule ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]  
RewriteRule . index.php [L]  

Then you should add some config content into you wp-config.php then relog in.

define('WP_ALLOW_MULTISITE', true);
define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', false);
define('DOMAIN_CURRENT_SITE', 'youdomian.com');
define('PATH_CURRENT_SITE', '/m/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);

Then you should visit the site a by server/m/a, Check you .htaccess and wp-config.php, watch the line ” RewriteBase /m/” and “define(‘PATH_CURRENT_SITE’, ‘/m/’);”