Microsoft has released the official videos for the Roadmap showing how to:
- Turn Roadmap on or off for your organization
- Welcome to Roadmap
- Create the Roadmap
- Connect a row to Project Online
- Connect a row to Azure Boards
- Share a Roadmap with a group
- Change who a Roadmap is shared to
- Add top-level key dates
- Change status in a Roadmap
- Remove a row or row item
Take a look and be ready to start using it.
Microsoft still doing the rollout so it might not be available for some tenants yet.
Check also the post from Brian Smith – Project Online: Getting Started with Roadmap he is explaining about the new services plans available, how to turn the Roadmap on.