Node.JS HTTP request using proxy leaks original IP address

Question

I'm trying to make GET requests to a public webserver (eg. https://*.com) through a proxy to hide my real IP address. The GET request returns a JSON Object which contains the IP Address the request originally was made from.

I'm currently using Node.JS with RequestJS and specifying HTTP proxy servers in the options object. However, this still returns my real IP Address and not the one from the proxy server.

I tried using HTTP as well as HTTPS Proxies with all different types of anonymity levels.

const headers = {
    "content-type": "application/json; charset=UTF-8",
    "user-agent": uA,
    "x-requested-with": "XMLHttpRequest"
};

const options = {
    url: 'https://*.com/*',
    headers: headers,
    method: 'GET',
    proxy: proxy //Random proxy. Format: http://0.0.0.0:0000
};

request.get(options,
    function(err, response, body) {
        console.log(JSON.parse(body));
    }
);