esp 4 pin

So I have a B550 Motherboard with a 8 pin and 4 pin connector to power my CPU,I am aware that only using the 8 pin is more than enough power to over clock and etc.. But I will be purchasing a new GTX 3090 and I have an AIO cooler for my CPU so I would like to take advantage of the 4 pin slot...

So my problem is this: I have built a computer and I was finishing with cable management, but then I noticed, the motherboard CPU power was 8 pin pluss 4 pin. I had the 8 pin EPS cable, but I had no 4 pin cable because of my Power supply. It's "modular" but don't support CPU/EPS cables So if I...