Install NordVPN on rock64

nordvpn.rock64.md

Installing NordVPN

https://support.nordvpn.com/Connectivity/Linux/1325531132/Installing-and-using-NordVPN-on-Debian-Ubuntu-and-Linux-Mint.htm

Configure

root@rock64:~# uname -a
Linux rock64 4.4.189-1230-rockchip-ayufan-gafadea9477b7 #1 SMP Thu Aug 22 16:18:51 UTC 2019 aarch64 GNU/Linux
root@rock64:~# wget -qnc https://repo.nordvpn.com/deb/nordvpn/debian/pool/main/nordvpn-release_1.0.0_all.deb
root@rock64:~# dpkg -i nordvpn-release_1.0.0_all.deb 
Selecting previously unselected package nordvpn-release.
(Reading database ... 62728 files and directories currently installed.)
Preparing to unpack nordvpn-release_1.0.0_all.deb ...
Unpacking nordvpn-release (1.0.0) ...
Setting up nordvpn-release (1.0.0) ...
root@rock64:~# apt-get update
...
root@rock64:~# apt install nordvpn
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  xsltproc
The following NEW packages will be installed:
  nordvpn xsltproc
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 6907 kB of archives.
After this operation, 25.7 MB of additional disk space will be used.
Do you want to continue? [Y/n] 
...
root@rock64:~# nordvpn set killswitch on
Kill Switch is set to 'enabled' successfully.
root@rock64:~# nordvpn whitelist add port 22
Port 22 (UDP|TCP) is whitelisted successfully.
root@rock64:~# nordvpn whitelist add subnet 192.168.88.0/24
Subnet 192.168.88.0/24 is whitelisted successfully.
root@rock64:~# nordvpn set autoconnect on
Auto-connect is set to 'enabled' successfully.
root@rock64:~# nordvpn connect
Please enter your login details.
Email / Username: USER@EMAIL
Password: PASSWORD
Welcome to NordVPN! You can now connect to VPN by using 'nordvpn connect'.
Connecting to Poland #88 (pl88.nordvpn.com)
You are connected to Poland #88 (pl88.nordvpn.com)!

Well,
whitelisting by this command didn't work
Nordvpn whitelist add port 67 and 68

found a solution for this
sudo iptables -A INPUT -i wlan0 -p udp -m udp --dport 67:68 -j ACCEPT

If anyone ever needs it.
Thanks Kamil.