How can I install Craft Commerce 2 alpha release? I tried following the installation instructions here: https://docs.craftcms.com/commerce/v2/installation.html

When I run composer install craftcms/commerce, it says: 


  Invalid argument craftcms/commerce. Use "composer require craftcms/commerce" instead to add packages to your composer.json.


So I then ran composer require craftcms/commerce, and it says:


  [InvalidArgumentException]   Could not find package craftcms/commerce
  at any version for your minimum-stability (alpha). Check the package
  spelling or your mini   mum-stability


I have added "craftcms/commerce":"@alpha" in the require field in composer.json also changed minimum stability to alpha ("minimum-stability": "alpha").

But it still is not working. Any thoughts? Thanks!
You have to contact P&amp;T (at support@craftcms.com) directly to get installation instructions.