Dabbling with web services as a hobby

This is more of a matter with how to get deploying your web backends/services than anything else. Sure, the easiest path would be to rent or pay for a server to deploy backend into. But as much as possible I'd look for a free alternative first then paid service if needed, regardless of usage limit since I would only have my long distance friends try it. I have had thought of port forwarding but unfortunately I am behind a CGNAT and suspiciously getting your own static ip costs a lot (vs local mi...