Step by step
Verify that you can sign in and write in your personal LiveJournal. Communities are not supported by this integration.
Choose LiveJournal in Publication channels. Enter a connection name, journal username (not an email or URL) and LiveJournal password. Check access, then save. Authentication uses HTTPS challenge-response and the stored credential is encrypted.
A destination draft creates a private LiveJournal entry, not a web-editor draft. Publish creates a public entry. Update the connection after changing your password. Do not weaken account protection to bypass an error.