I am going to assume you already know what http tunnels are for, and also ngrok.
1
Multiple ways to get to this tab, including the tower icon bottom left or good old cmd+shift+p
2
Choose your port of choice, and sign in through MS/GitHub. Very self-explanatory.
3
Change visibility to public, and optionally change protocol to https if requied.
4
This dialog box shows up the first time you access the tunnel link. And that's about that.
And et voilĂ ! We have a free ngrok alternative right within our beloved Visual Studio Code!