redirect your computer port to url

I'm not asking to open ports on the router terminal, i know how to do that

i remember once i saw a youtube tutorial that he used a terminal application(linux) that gives you a super long URL and it goes to your computer

it is useful to access between different networks, for example:

• in my job i have the laptop in the wifi network and the computer in another different, and i would like to access 192.168.0.33:8080 from the computer to access the laptop, but the laptop its in 192.168.31.21

• same story at my house, I have an access point on my room, from the laptop i can access the computer because its in the main network but from the computer i cant access the laptop

• or even to share a live server to a friend

i don't know how to search it, in fact I've been searching for a week.