Install kobotoolbox on server

Best regards kobotoolbox community
I request for support with the following situation.

I have a web portal with the address,
I need to make use of the port redirection in such a way that is redirected to the virtual machine installed on a host ( of a subnet, this machine is where I am trying to install Kobotoolbox. => (kobotoolbox app)

as should be the configuration of my --setup

thanks for your help