Actually the problem is the USB hub I used to connect M4 is unplugged from the PC ^^"
Thanks for your reply

I have a NanoPi M4 with eMMC module(Android 8.1), I need to debug my app on the board via adb. I have tried adb over TCP and adb over USB, neither of one worked. For adb over TCP, I configured the network to make my desktop (Windows 10) and NanoPi M4 under the same private LAN. I followed the step i...