Ruby on Rails uses a '_method' parameter in the POST body for legacy clients like this
Many frameworks have support for this. Check for "HTTP method override" techniques for whatever technology you're using on the server end. Rack (Ruby) and Express (Node.js) have method override middleware that can handle this easily. I've also built a .NET implementation. They typically search for the X-HTTP-Method-Override header and fallback to the _method querystring parameter.