Let the python project run when the Jetson nanocomputer boots up

Hello, I’m trying to run the alpr software I wrote on jetson nano. I tried adding command in startup apptication but it works wrong. I am trying to read with simultaneous camera in my alpr software. with usb camera. But I don’t understand what is the reason. It doesn’t work at startup

Os:ubuntu 18.04
python:3.9
usb camera