Userdoc supports native integration with Jira (using a Jira API key), and actually supports multiple Jira integrations, meaning you can sync your User stories across multiple platforms.
A Userdoc account, and an existing project you wish to integrate with Jira.
A Jira Cloud account, with an existing project you wish to integrate with (Note: Userdoc only supports integration with cloud hosted Jira, not with Jira Server)
Inside project settings in Userdoc, click Story Integration.
Click on the ‘Connect your Atlassian Jira Account’ button to view the Jira Integration Setup screen.
From the dropdown menu, choose the Jira project you want to integrate the Userdoc project with.