OwnTone can access remote streams via proxy. This is different to a reverse proxy.
HTTP-proxy
To configure a proxy the environment variables https_proxy=http://<IP>:8888/
and http_proxy=http://<IP>:8888/
are respected. This behavior is inherited from libcurl.
Example:
export https_proxy=http://<IP>:8888/
export http_proxy=http://<IP>:8888/
owntone -d1 -P /tmp/owntone.pid
Other proxies
Other proxies are possible as well. See the documentation of libcurl for those.