I'm trying to use proxies for http requests with the vibe.d library like this:

HTTPClientSettings settings = new HTTPClientSettings;
settings.proxyURL = URL.parse("http://gb.smartproxy.com:30000");
auto response = requestHTTP("https://dlang.org", (scope req) {
    req.method = HTTPMethod.GET;
}, settings).bodyReader.readAllUTF8;

writeln(response);

As soon as I enable the proxy settings I get errors like this on pretty much every site I try with:

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>302 Found</title>
</head><body>
<h1>Found</h1>
<p>The document has moved <a href="https://dlang.org/">here</a>.</p>
</body></html>
It works fine when I do it in python with the requests library with the same proxies