How to add self-signed certificate for SSL connection?

Question

Android

Good day. I'm trying to set up an SSL connection to my server using a self-signed certificate.
But I can't add my certificate to TrustManager, I get an error:

SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.

Caused by: java.security.cert.CertificateException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.

To bypass, I created my own TrustManager, but this solution does not seem right to me.

static class MyTrustManger implements X509TrustManager {
        @Override
        public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {

        }

        @Override
        public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {

        }

        @Override
        public X509Certificate[] getAcceptedIssuers() {
            return null;
        }
    }

 public static SSLSocket createSSL() {
        try {
            KeyStore trustStore = KeyStore.getInstance("BKS");
            String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
            TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(tmfAlgorithm);
            InputStream trustStoreStream = context.getResources().openRawResource(R.raw.certstore);
            trustStore.load(trustStoreStream, "1234".toCharArray());
            trustManagerFactory.init(trustStore);


            TrustManager[] trustManagers = trustManagerFactory.getTrustManagers(); //Не работает
//            TrustManager[] trustManagers = new TrustManager[]{new MyTrustManger()}; //Работает

            KeyStore keyStore = KeyStore.getInstance("BKS");
            KeyManagerFactory keyManagerFactory = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
            InputStream keyStoreStream = context.getResources().openRawResource(R.raw.clientkeystore);
            keyStore.load(keyStoreStream, "1234".toCharArray());
            keyManagerFactory.init(keyStore, "1234".toCharArray());

            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init(keyManagerFactory.getKeyManagers(), trustManagers, new SecureRandom());
 
            return (SSLSocket) sslContext.getSocketFactory().createSocket(host, 1443);
        } catch (Exception e) {
            return null;
        }
    }