Hi farhatyakubov,
You could refer to the following thread for UART usage on Orin NX/Nano.
OrinNX : How to check UART is working? - #3 by KevinFFF
It should be /dev/ttyTHS0 for UART1
The overlay package for Orin series is bout usb firmware to fix packet lost issue.
You could just extract that in your BSP package before flash the board to apply it.