A Keepsake Sound product
This installs Heirloom for macOS. You can choose the Audio Unit, the VST3, or both on the next screen.
The Audio Unit installs to /Library/Audio/Plug-Ins/Components and the
VST3 to /Library/Audio/Plug-Ins/VST3. Both are the standard locations
every host already looks in.
Heirloom plays from a library file called Heirloom.ksbank, which is
about 31 GB and downloads on its own. It is not inside this installer.
If the library is already sitting in your Downloads folder, Heirloom will find it by itself. If you keep it somewhere else, open the plugin and use Locate Bank to point at it once. Heirloom remembers where you put it.
Activation happens inside the plugin, not here. Have your key to hand for the first time you open it.