I am making a post request to the text summarizer endpoint using HttpUrlConnection.

				URL url = new URL(apiUrl);
				HttpURLConnection client = (HttpURLConnection) url.openConnection();
				client.setRequestProperty("content-type", "application/json");
				client.setRequestProperty("x-rapidapi-host", "text-analysis12.p.rapidapi.com");
				client.setRequestProperty("x-rapidapi-key", "hidden");
				client.setRequestMethod("POST");
				client.setDoOutput(true);

				String jsonBody = "{" +
					"\"language\":\"english\"," +
					"\"summary_percent\":" + summaryPercent + "," +
					"\"text\":" + "\"" + myTestString + "\"" + "}";

				//POST to endpoint first
				try(OutputStream os = client.getOutputStream()) {
					byte[] input = jsonBody.getBytes("utf-8");
					os.write(input, 0, input.length);
				}

For some reason, when I make the request via RapidApi it works, but when I do it via Java the response is always this:

{3 items
"time_taken":0.0007703304290771484
"msg":“validation error, incorrect data passed to the server”
“ok”:false
}

I have made sure my JSON body passed in is in good format. Any ideas?