In addition to what Jim said there's one thing to know if you're going to do this is that opening ports to the outside is technically a security risk. As long as you know this and can accept the risks doing so, go for it.
Regarding how, I'd recommend looking up in a search engine for your router manufacturer and model with how to port forward, e.g. TP Link Archer VR 2100 port forwarding, and see what comes up. After you forward the port(s) you want to use you can test open ports using a tool like this...
https://canyouseeme.org/
