How can I have incoming I2P connections connected to me through OpenVPN?

Question

openvpn

My ISP does not provide the ability to open ports. To do port forwarding, I use the portmap.io service. Portmap uses OpenVPN for port forwarding, but there is no internet on the VPN itself. I opened port 3256 for TCP and UDP, entered this port in the settings and entered the IP accessible from the Internet, that is, the external IP of the VPN. But all the same, the Network says in I2P: blocked by the firewall. How to be?