I'm lazy and cheap...I would just cut a window out and put a inexpensive gable vent in the window cutout.
https://www.lowes.com/pd/CMI-12-in-x-12-in-White-Rectangle-Steel-Gable-Vent/3284522
https://www.lowes.com/pd/CMI-12-in-x-12-in-White-Rectangle-Steel-Gable-Vent/3284522