How can i Port Forward for WAN Attacks in Kali Linux HELP

so i tried to hack android using msfvenom and metasploit on LAN and everything worked fine but that only happens when i am connected to that specific wlan ip adress with which i created the apk ,i want to do a WAN attack but i have no idea how to port forward , the problem is that i used my mobile hotspot to do the LAN attack and i dont have a router , i use a modem to access the net ,however when i created another apk for LAN attack and i use the computer's in built kali hotspot and used its ip to attack and it worked fine but i need to make it work so i can attack even if the victim is on a cellular data , please help me how do i do it