Is it possible to configure two subdomains for an IP address?

["Rex C. Eastbourne" <rex.eastbourne@xxxxxxxxx>]

Hello,

I am completely new to Apache. I have a static IP address that's being hosted on an Ubuntu server. (I do not own a domain name yet.) I would like to have two versions of a web app on my IP address (let's call it X.X.X.X):

test.X.X.X.X
production.X.X.X.X

Is this possible with Apache? I have gone through the Apache documentation on VirtualHosts, which I presume is how I would configure this. Here is what I have tried putting in my httpd.conf file

NameVirtualHost *:80

<VirtualHost *:80>
    DocumentRoot /www/production
    ServerName production.X.X.X.X
</VirtualHost>
    
<VirtualHost *:80>
    DocumentRoot /www/test
    ServerName test.X.X.X.X
</VirtualHost>

However, when I do this, I get the following error message:

[error] VirtualHost *:80 -- mixing * ports and non-* ports with a NameVirtualHost address is not supported, proceeding with undefined results

This is probably a very elementary error, but I am new to Apache and am having trouble understanding many of these terms. Could anybody provide some guidance on how I can get started with this setup?

Thanks,

Rex