Enabling TLS with 'loki.source.syslog'

I would like to know if it possible to enable TLS with Alloy on the loki.source.syslog on the listening port. I “simply” want to do RFC5424 over TCP-TLS.
I have read the documentation (loki.source.syslog | Grafana Alloy documentation) but it is still not clear…

There is the tls_config with ca_file, cert_file and key_file. But the ca_file is defined as CA certificate to validate the server with and cert_file and key_file as Certificate/Key file for client authentication.

So either tls_config is to configure TLS connection with some other servers (Loki?) (And I would need potentially a stunnel to add TLS to Alloy loki.source.syslog) or the wording in the documentation is not correct (does not make sense to have the (private) key_file for client authentication).