How can I send a Base64 Image?

I'm looking to make a post request with a base64 image. When I make the request, I get an error called "ERROR_IMAGE_SIZE_0"

  import javax.net.ssl.HttpsURLConnection;
import javax.net.ssl.SSLContext;
import java.io.*;
import java.net.*;
import java.util.Base64;

public class Main {

    public static void main(String args[]) throws IOException {
        File originalFile = new File("sec_token.php.png");
        String encodedBase64 = null;
        try {
            FileInputStream fileInputStreamReader = new FileInputStream(originalFile);
            byte[] bytes = new byte[(int)originalFile.length()];
            fileInputStreamReader.read(bytes);
            encodedBase64 = new String(Base64.getEncoder().encodeToString(bytes));
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        System.out.println(encodedBase64);
        HttpURLConnection con = (HttpURLConnection) new URL("http://2captcha.com/in.php?key=61f5d7a6cccc2db4e7c503a59f4f7e&method=base64&imginstructions="+encodedBase64).openConnection();

        String USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0";
        System.out.println("User agent: " + USER_AGENT);
        //add request header
        con.setRequestMethod("POST");
        con.setRequestProperty("Host", "2captcha.com");

        con.setDoOutput(true);
        DataOutputStream wr = new DataOutputStream(con.getOutputStream());
        BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while((inputLine = in.readLine()) != null){
            response.append(inputLine);
        }
        String res = response.toString();
        System.out.println(res);
    }
}