I think I have got it
Create a .htaccess file and put it in the generator folder with the below.
Make sure to change the IP addresses
order deny,allow
deny from all
allow from 192.168.1.5
allow from 127.0.0.1
<FilesMatch "sitemap.xsl">
allow from all
</Files>
You will need to set the IP addresses:
192.168.1.5 - This is your IP
127.0.0.1 - This is the server IP