Does the Librem One tunnel give one their own IP address to tunnel a server through?

A very long while ago, I wanted to port forward, but couldn’t because I didn’t have access to the router. During this time I remember reading that a tunnel could help with this. Is the Librem One tunnel this type of tunnel, or is it more like a VPN?

Let me rephrase that for you.
Is Librem One tunnel having public IP allowing me to control inbound traffic or it is hidden behind private address and firewall allowing only outbound connections?
I never used that so cannot answer, let me do a quick check though… ok, it’s not that easy to check, doesn’t allow me to register account saying my mail is in use (I already have forum acc, shop acc, git acc - no idea which one of them conflicts).
Anyway I suspect it would be rather private internal IPv4 IP hidden behind NAT/PAT and public IPv6 (if the prefix is assigned at all). But this is mere speculation based on experience with these kind of things.