Dear Eustorgio,
The active backplate BP-EVB3090FE is designed for BP-VG3090FE-V2 water block.
You can see the third picture in the following link.
Would you send us an email? We will send you more pictures to show how to connect these two water blocks.
shopservice@bitspower.com.tw
https://shop.bitspower.com/index.php?route=product/product&product_id=8085&search=3090fe