Expanding metadata through reverse proxy?

[icsy7867]

This is definitely not a YOURLS issue,. My docker container on port 80 seems to work properly with things like Facebook, slack etc.... Where there is a little preview of the short links destination.

However I run the docker container with an nginx reverse proxy, but this seems to break these links (slack calls it "unfurling"). I'm wondering if someone smarter than I knows how to tell nginx or apache reverse proxy to handle these?