Hi ismailyesilyurt.80, you can connect momentary push-buttons for Power-On, Reset, and Force Recovery to the pins on the J40 button header, please refer to pages 6 & 7 of the Jetson Nano Developer Kit User Guide: https://developer.nvidia.com/embedded/dlc/jetson-nano-dev-kit-user-guide
J40 Button Header
You can also simply short these pins with a standard 2.54mm shunt jumper if that’s easier.