Front IO connector

So I'm helping a friend move his prebuilt to a new case. I've built everything except for 1 step, the front IO connector. the old pre built was an Omen 25L with split-up in connectors which connected through a hub. (motherboard - Dorado 4L). Now with the Corsair 3500x, there seems to be a regular front io connector (the ones i'm experienced it with my 8+ built-from-scratch pc's. What should I do?!

In the picture i'm holding the front IO installed with the 3500x