Github API is responding with a 403 when using Request's request function

As explained in the URL given in the response, requests to GitHub's API now require a User-Agent header:

All API requests MUST include a valid User-Agent header. Requests with no User-Agent header will be rejected. We request that you use your GitHub username, or the name of your application, for the User-Agent header value. This allows us to contact you if there are problems.

The request documentation shows specifically how to add a User-Agent header to your request:

var request = require('request');

var options = {
  url: 'https://api.github.com/repos/request/request',
  headers: {
    'User-Agent': 'request'
  }
};

function callback(error, response, body) {
  if (!error && response.statusCode == 200) {
    var info = JSON.parse(body);
    console.log(info.stargazers_count + " Stars");
    console.log(info.forks_count + " Forks");
  }
}

request(options, callback);

From C# and using HttpClient you can do this (tested on latest .Net Core 2.1):

using (HttpClient client = new HttpClient())
{
    client.DefaultRequestHeaders.Accept.Add( new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));

    client.DefaultRequestHeaders.UserAgent.TryParseAdd("request");//Set the User Agent to "request"

    using (HttpResponseMessage response = client.GetAsync(endPoint).Result)
    {
        response.EnsureSuccessStatusCode();
        responseBody = await response.Content.ReadAsByteArrayAsync();
    }
}

Thanks