sudo iptables -L                                   # list
sudo iptables -t nat -L -v                         # list nat table

sudo iptables -A FORWARD -i wg0 -o wg0 -j ACCEPT           #ans Ende der chain (append)
sudo iptables -I FORWARD -i wg0 -o wg0 -j ACCEPT           #an den Anfand der Chain
sudo iptables -I 4 FORWARD -i wg0 -o wg0 -j ACCEPT         #an 4. Stelle der Chain

sudo iptables -t nat -v -L -n --line-number        # list nat table rules numbered
sudo iptables -t nat -D POSTROUTING 6              # delete rule from nat table in chain POSTROUTING number 6