The feature is currently available to users in the Windows Insider Beta program, which you can sign up for at any point from the Windows Update screen on your PC.
Support for Android apps on Windows 11 works similarly to how the new operating system supports Linux apps. Essentially, it runs the apps in a special subsystem that lets them work natively on your PC.
Users interested in trying out the new system can download the latest Windows 11 update from the Windows Insider Beta channel.