Hi Sithum,

This is not mandatory for they are many online tunneling services that let you enable port forwarding with even accessing the router (even if you’re connected to a wired network), though these services might be down due to black hat hacking and phishing. You can check out the following examples:

Serveo Service

Ngrok

Alternatively, you can send reverse connections to an intermediate computer (a server on the internet), this way you won’t need to configure anything, and use a VPN or TOR to directly connect to this middle server and control the target, this way you won’t need to enable port forwarding anywhere so something like this:
Target —–(reverse connection) —–> Middle server <——-(Direct connection over VPN/TOR) ——- Your computer

Kindly note that the above method won’t be covered in ANY course, due to the above-mentioned reasons and for better security measures.

The 1st thing to do is to try and enable port forwarding in your router assuming that this is possible. You have to to check first if the port(s) is open again using https://canyouseeme.org while keeping the below notes if it didn’t work:

1. You did not configure the router properly to allow for port forwarding, so please make sure that you do some research of your router model, cause every router model has a slightly different method to enable port forwarding.

2. The port is not actually open in Kali, so make sure that the service is actually running in Kali on the required port.

3. Your ISP (Internet Service Provider) does not allow you to forward ports, so please call them to check/

As for the above method using intermediate servers, as mentioned above, it won’t be covered in any course, but you can set up your own server for the procedure, and search online if you can find anything related to this subject, but I can’t guarantee one way of doing this, so it’s best if you do further research on this… I hope this clarifies better.