Linux support?

Just acquired these components, excited to get started, but I am curious why I don't see an option to compile for Linux 64 bit?

The sgcWebSocketsD10_4.bpl project has the following platforms listed:

* Android 32 bit
* Android 64 bit
* iOS Device 64 bit
* iOS Simulator
* macOS 64 bit
* Windows 32 bit
* Windows 64 bit

However when I look to add Linux 64 bit, the dropdown for Target Platforms says "Add Platform..." but is disabled...

So it does not seem possible to support Linux 64 bit, at least not with the Delphi compiler. Please advise.