As usual, you can add the Qt 6.1 Alpha to the existing online installation by using the maintenance tool. Or you can do a clean installation by using the Qt Online Installer. Qt 6.1 Alpha source packages can be downloaded from the Qt Account portal and the download.qt.io as well.
Additional libraries for the Qt 6.1 Alpha are released as source packages only. Those can be downloaded from the Qt Account portal and the download.qt.io as well. We will include those in the Qt online installer latest in beta phase.
We are targeting to release Qt 6.1 Beta ~ two weeks after the Alpha release. The target is to publish updates to the Alpha release regularly so please check possible updates from the maintenance tool every now and then.
Please start testing the Qt 6.1 Alpha now and report all your findings in Jira immediately.