since yesterday there is an alpha program here on the platform which gives you access to the alpha versions of certain extensions. But first of all, alpha versions are never suitable for live operation.
In order to gain access to the Alpha program, you simply have to apply under Control Panel => User Groups => User Groups => Alpha-Tester => Apply for Membership.
If your application is accepted, you will have access to the package server (https://tkirch.dev/update/alpha/), special forums and special Discord channels (provided you have linked your Discord account to your account here).
The first extensions for alpha testers will include "Gamers Manager" and "Paywall".