Version 11 required a separate addon for FTP capability. I don't see this as an upgrade option when I try to upgrade. Thanks for your help.
(Basic FTP is built-in. The add-on is for things like SFTP and FTP over SSL.)
If you already bought the add-on for Opus 11, you don't need to buy it again when you upgrade to Opus 12. Ownership of the add-on carries over to the new version.