This app allows you to create a Jira project and a Confluence space from a transition of a Jira issue.
Make sure somewhere in Jira there is an Issue Type that has the transition you have configured before and at the same time the Custom Field is available.
After the transition happened, the app will create the Jira project and the Confluence space with the settings you configured.
Documentation
Have a look at our Documentation page to read about the glorious details of Viable Project Creator.