EDIT no wait, this post is about secure, not hosting/tunneling in general. This comment is off topic ig.
I would like to avoid paying for a VPS
Oracle cloud free tier, but it does have a history of randomly killing the VPS’s created.
Public ipv4 addresses are scarce, and becoming more expensive now. You are probably going to have to shell out some cash if you don’t already get one as part of your internet plan.