There are two types of SOAP Books: regular and practice.
You can create and use practice SOAP books for free but they are limited to 50 clients, and all SOAP Charts from a practice SOAP book will carry a watermark. There is no need to get a subscription for a regular SOAP Book.
You can use a regular SOAP Book for free for
60 days. After 60 days, you will need to pay a subscription fee for each
user of that SOAP Book. The software will tell you when your
subscription has expired.
After your trial period ends, if you are a subscription administrator you will
see a Subscription tab inside the Practice tab. The
Subscription tab will have a Subscribe... button. Click on the
Subscribe... button to start the subscription process.
Note that you will need to have an Internet connection to be able to buy your subscription.