I have nothing plugged into that lol
But I can't find the plug that goes into that either
Your power supply has an EPS12V connector - 8 pins
Your motherboard will accept either an 8 pin or a 4 pin CPU power connector, just take the rubber cover off the socket to expose the other 4 pin sockets, its a keyed connection, only fits one way.
The 8 pin connector is designed to also be converted to 2x4pin, for those motherboards that only have a 4 pin connector.