Just found this tutorial
https://arashmilani.com/post?id=53
I think I need these lines, correct me if i'm wrong...
iptables -A FORWARD -i tun+ -j ACCEPT iptables -A FORWARD -i tun+ -o eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT iptables -A FORWARD -i eth0 -o tun+ -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -o tun+ -j ACCEPT