open port 2707 with openvpn

hello everyone,

i installed openvpn on my router wndr3800, my connexion vpn is good, but i can't open port 2707 on the serveur vpn, i'm open port 2707 on the site on my vpn provider.

my iptables is :

iptables -I FORWARD -i br0 -o tun0 -J ACCEPT

iptables -I FORWARD -i tun0 -o br0 -J ACCEPT

iptables -I INPUT -i tun0 -j REJECT

iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE

my network is the picture

What should i do to open port 2707 on my vpn connexion?

Thank