[FEATURE] Add iptables rule in program

[RaspberryTech01]

Is your feature request related to a problem? Please describe.
On a fresh system and running the program from source, the iptables rule that is required to allow data to client is not present.
Users can connect to the VPN and send data but no data is received. To mitigate this the iptables rule is required.
Describe the solution you'd like
Implement sudo iptables -t nat -A POSTROUTING -o enp0s3 -j MASQUERADE into the program.
enp0s3 needs to be the correct interface such as eth0, eth1, enp1s3 etc.

Describe alternatives you've considered
Creating a .sh file which runs the command and then starts the program up.

[RaspberryTech01]

Put on low priority.