Currently, there are two “Deploy to iTunes Connect” steps, one uses fastlane deliver, one uses Application Loader. Both require to enter username and password but it would be great to be able to use a connected Apple account instead.
Minor detail: “iTunes Connect” was renamed to “App Store Connect”. New users may be confused by the old name and steps should be renamed to match the new naming.
For that we already have a card in our backlog, which was just bumped so that it should be processed soon. Can’t promise anything right now, other than “I did set it to the highest priority” though it might still get de-prioritised along the triaging process.