ESP32 cam board and pins

I am following this tutorial to save a picture using the ESP32 cam board. I am trying to add a PIR sensor.

whenever I try to use any pins to enable wake on external pin high, there is an error either because of interruption with the camera initiation or sd card.

what can be done?

There may not be any pins that are unused if you're using the SD card, take a look at the comments on the page that you linked to.