How to run Iodine for IP over DNS

https://code.kryo.se/iodine/

prerequesites:
publicly reachable ipv4 or ipv6 server with domain myserver.example.com (your server)
publicly reachable ipv4 or ipv6 nameserver where you can add your server as a dns server (your server or another one)
root access to your server

on dns:
sub.example.com IN NS myserver.example.com

on server myserver.example.com:
sudo apt update
sudo apt install iodine
sudo /usr/sbin/iodined -f -c -P pass 10.0.0.1 sub.example.com
sudo echo "1" | sudo tee -a /proc/sys/net/ipv4/ip_forward
sudo /usr/sbin/iptables -t nat -A POSTROUTING -o ens192 -j MASQUERADE

to find out interface:
ip addr show

to run in background:
sudo /usr/sbin/iodined -c -P pass 10.0.0.1 sub.example.com

on linux client:
sudo /usr/sbin/iodine -f -P pass sub.example.com

on smartphone:
Tunnel Top Domain: sub.example.com Password: pass