From Xojo Documentation
| This method is only available on Windows and Linux platforms.
For cross-platform development, use ＃If...＃Endif with the Target... specifiers to make sure you will not attempt to use this method on an incompatible platform.
Adds the passed item to the System Tray via the TrayItem class.
AddTrayItem returns a Boolean that indicates success or failure. If it returns True, the TrayItem was added successfully. The System Tray is supported on Windows and Linux only. See the TrayItem class.