Help porting to Xperia X running Sailfish
How do I install UB Ports on a sailfish device, that has no android at all
I tried the UB Ports installer but it fails to recognize the device even of its in fastboot mode
You cannot install Ubuntu Touch on a device that it has not been ported to. That's why the installer will not recognize your device.
If you would like to port Ubuntu Touch to your device (porting is not the same as installing), please see the documentation.