@Kamarguera, I guess the network adapter of your Kali image is configured as NAT in VM settings of Virtualbox. Change this to 'Bridged Adapter' and attach it to the W7 interface (wired or wifi) that is live. This makes Kali to pick an IP from your LAN DHCP (you may want to set static IP on that Kali interface if you prefer). This eliminates the NAT problem within your machine. Now people in your LAN should be able to access the page on Kali_IP
ort. If you want to have people from internet access it, you have to open port (and/or configure port forward) on your internet router. They should be able to access the page on Your_Public_IP
ort.
I am assuming that you have complete permission for this from company/users and is not a attempt to illegally harvest real credentials.