You can use a genuine Windows 10 Pro product key to activate Windows 11 Pro. Generic Keys for Testing:
Yes, if you purchase a legitimate Windows 11 Pro key. Go to Settings > System > Activation > Change product key. Enter the valid key. The Insider build will convert to a fully activated, genuine Pro edition, but you will remain on the Insider track (still receiving beta updates) unless you opt out. windows 11 pro insider preview activation key