If you want to try it, you need to:
1. Enable developer mode in Windows 10
2. Download the msix package from the artifacts page of the latest build in Azure pipelines
3. Extract the msix, with 7-zip for instance.
4. The directory which contains the application manifest should be moved to a suitable location.
5. Run in Powershell: Add-Appxpackage -Path <path>\App manifest.xml -Register
Windows Terminal appears in your start menu.
> Otherwise, you'll need to wait until Mid-June for an official preview build to drop.