First, look under the release documentation and search for the deb package. In my case I’m install the amd64 version.
Then, right-click on the “powershell-preview_7.0.0-preview.2-1.ubuntu.18.04_amd64.deb”, and select “Copy link address“.
This is also something you could script out. It’s quite useful in scenarios where your apt repositories don’t have the latest version of something but you still need or want it.