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:
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.