On this page:

Invite external user to join the checklists app

Navigate to the Didit - Checklist hub in Confluence, Jira, or via the web at app.checklist.info.
Choose the template you would like to share externally.
Click on “edit” next to “TemplateManager.”
Enter the user’s email address and check “Invite external user to join the checklists app” if you want them to receive an invitation email. Then click “Add and invite.”
The user will then receive an email and can sign up.
After logging in, the external user now has access to that checklist template and all its checklists via the web at app.checklist.info.