The following (HTTP GET) works.
$ wget https://odrs.gnome.org/1.0/reviews/api/ratings
But, I get the following error when trying to HTTP POST to ODRS.
Error 502
Bad Gateway
CDN77 server is unable to reach website’s origin server.
If you’re a Visitor…
Please try again in a few minutes. If the problem persists for more than 30 minutes, try contacting website owner via a different channel.
As the Website administrator…
Please make sure the firewall on your origin server is disabled. It might be blocking the requests from the CDN77 servers.
If that is not the case, take a look at the article on troubleshooting error messages in our knowledgebase.