Problem with mounting new fan cooler - Hp Z220 CMT

HI

I get spare motherboard from hp z220 cmt and I want use it in another computer, so I get original HP cooler with sink for HP Z220 CMT, its 643907-001.

Problem is - there is no how to mount it on motherboard..  there is no latch.. no how to attach it.

Should motherboard have backplate? Help please

Thanks