If you are using Docker for your Peertube, you need to modify the `docker-compose.yml` file to open port 5269 of the `peertube` container, so that the outer world can connect to it.
You need to add [DNS records](https://prosody.im/doc/dns) allowing remote servers to find "room.your_instance.tld" and "external.your_instance.tld" components.
If you are **not using the standard `5269` port**, you must also add a SRV record for `_xmpp-server._tcp.your_instance.tld.` (same as above, just without the `room.` prefix).Of course, you can also add this record if you use the standard port. It will also work.