what brand of power supply do you have?
If your power supply supports the 16 pins you could connect the power supply original 16 pins cable to power supply and then to the lian li strimer v2 cable. if this not the case you could buy another extension cable that is 16 pins and the other side is 3x PCI-e from cablemod item number: 23944528 you could add it in the search of digitec and there are multiple colors if you would like to have another cable color.