Hello,
the thing is for your scanner there are two AIs available, namely SilverFast Ai and SilverFast Ai IT8 as you can see here:
https://www.silverfast.com/order
Say if you haven't got Ai IT8, which naturally comes with targets, you cannot calibrate your scanner using SF.
It varies BTW and while I've got Ai IT8 for my Nikon I've got plain Ai for my Epson which came with MonacoEZcolor with which I can calibrate that flatbed.
I don't know what is included with your model but in short either you've got something to calibrate your scanner already or you may look for a free spot on the wall and start banging your head into it 8-}
Alternatively you may upgrade the version you've got and yes, IT8 targets ARE costly.
So sorry for the bad news, but as it seems you simply did not order the right version,
Juergen