Getting 400 (Bad Request) when placing order c#

Alpaca Integration Applications
1

Can anyone spot why I keep getting (Bad Request):

var endpoint = “https://paper-api.alpaca.markets”;
var client = new HttpClient();
var request = new HttpRequestMessage();
request.Method = new HttpMethod(“POST”);
request.Headers.Add(“APCA-API-KEY-ID”, “”);
request.Headers.Add(“APCA-API-SECRET-KEY”, “”);
request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue(“application/x-www-form-urlencoded”));
request.Properties.Add(“symbol”, “APPL”);
request.Properties.Add(“qty”, “1”);
request.Properties.Add(“side”, “buy”);
request.Properties.Add(“type”, “market”);
request.Properties.Add(“time_in_force”, “day”);
request.RequestUri =
new Uri(endpoint + “/v2/orders”, UriKind.RelativeOrAbsolute);
var response = await client.SendAsync(request);
if (response.IsSuccessStatusCode)
{
var contentString = await response.Content.ReadAsStringAsync();
dynamic contentJson = JsonConvert.DeserializeObject(contentString);
}
else
{
Console.WriteLine(response.ReasonPhrase);
}

I also tried building request with content as below but with same result:
var values = new Dictionary<string, string>
{
{ “symbol”, “APPL”},
{ “qty”, “1”},
{ “side”, “buy”},
{ “type”, “market” },
{ “time_in_force”, “day” },
{ “limit_price”, “0” },
{ “stop_price”, “0” }
};
request.Content = new FormUrlEncodedContent(values);