Please just share the result of the following command on your board.
$ cat /etc/nv_tegra_release
Okay, we can start from this.
Please refer to the following topics for the users have enabled PPS on their case.
Enable PPS on Jetson Linux 35.3.1 for Xavier AGX - Jetson & Embedded Systems / Jetson AGX Xavier - NVIDIA Developer Forums
Pps_gpio interrupt not asserted - Jetson & Embedded Systems / Jetson Orin NX - NVIDIA Developer Forums
Custom Device Tree Overlay - Pin Mapping - Jetson & Embedded Systems / Jetson Orin NX - NVIDIA Developer Forums