I have safari (and safari web technology preview) installed under MacOS 10.13.
How do I install the prebuild? If I go to https://lastpass.com/lpp/
and click on the downloaded file I get 'Safari can't install this extension'. Drag/drop to extension panes in safari preferences doesn't appear to help either.
I hit a possible issue in the plugin and before debugging/reporting further thought it worth trying the latest prebuild version.