It's a ROCKPro64 board
Discussion
Roger. Is it possible that it's not booting? Are to seeing orange and green flashing lights on the network port?
I think so. 
I'm not sold on it booting.
Logging to your router and look for the device's IP address then login to that at https://ip-addrress
If you I don't see an IP for this, it didn't boot.
I think you are right, but now I'm working on a different problem before I can do that:
Meh. Factory reset it. Set it all up again. Use the same SSID and password so your WiFi devices all reconnect. That's not a big deal, just more work.
Alternatively, you can use a program like Angry IP scanner to scan for devices on your network.
Okay. Did all this. 👍
It definitely didn't boot. Now what do I do?
Figure out why it didn't boot? 😜
Reflash the sd card. Still no boot? Plug an HDMI cable into it and hook it up to a monitor or TV and see what it says.