Create a site for OneClicks

Go to Administration and Management > Sites Admin and click Add a Site.
Fill in Site Name, Short Name fields and click Save Changes.
The new site basic info will be saved and a new window will prompt for more details.
Enter the URL and Linkdomain fields and scroll down to Biller Details section in order to enter the Site Id provided by Vendo and click Save Changes.
Go to Add New Join Option, select the initial cost, recurring cost, join form text, Vendo identifier and click Add This Join Option.