Journey Welcome Notification Question

Summary: How can we get our customized DM for the ChecklistWelcomeReport which is providing details that are set up on the offer into the Alerts Composer notification?

Content (required):We have not implemented Journey's yet. We have attempted to get a test pod set up to see what it looks like with out information. One of the major questions that I'm unable to get answered via any of the documentation is how can we get our customized DM for the ChecklistWelcomeReport which is providing details that are set up on the offer. From what I can tell in reviewing any documentation, we are told that switching to the Alert Composer notification is how we need to have the Journey's set up.