I need help configuring my macbook air (2012) to share a VPN connection (using OpenVpn) with another PCs

My current configuration consist of a macbook air purchased in 2012 running openVPN software. Open VPN encrypts traffic leaving the wifi connection with no issues. However I want to share this encrypted internet connection with other computers. I can easily share internet connection with other computers when openvpn client application is off. I tried creating nat rules and enabling packet forwarding with no luck

for example
sudo sysctl -w net.inet.ip.forwarding=1
nat on utun1 from en0:network to any -> (utun1)