Turn localhost into a link.
Run MeshLink against a loopback service, receive a private HTTPS link, and share it with the people who need temporary access. No inbound port forwarding and no tunnel infrastructure for you to operate.
$ MeshLink 3000
✓ link ready
https://link.meshlatch.com/#MLK1.AAAA...
→ http://127.0.0.1:3000