Cloudflare Quick Tunnels

Cloudflare Quick Tunnels creates a free, encrypted public URL for a local app with one command. It connects your machine to Cloudflare through an outbound-only encrypted connection, so you do not need a Cloudflare account, DNS records, or open ports.

This makes it possible to access localhost from outside your network. Traffic arrives over HTTPS through Cloudflare, while your router does not accept inbound traffic, and your machine stays private.