Some versions of 10.3 Rio do not have IntraWeb included, most notably the Community Edition. Some web installers require you to manually select it, while some non English web installs do not have it at all.
The English ISO (and likely other languages) have IntraWeb included.
It’s still Free!
Not to worry. A free download of IntraWeb 14 will be available to all 10.3 Rio users, even if your install does not include it. The update is not ready yet, but it is coming soon. You can read more here.
Paid users with current keys should use IntraWeb 15 instead.