Dell Optiplex 3046 Front Panel Fan Placement

My processor is over 71 degrees under load and it bothers me. To prevent this, I ordered a fan to be installed in the front a few days ago. The SSD section needs to be cut a little, if I don't cut it, the fan won't fit. And I don't know where to connect the fan, I don't see any other fan connectors on the motherboard. Can you help me? (I use Google Translate, my English is not good. Sorry if the description is not correct)