React Native HTTPS Api calls works in IOS but not working in Android

Step1 : create a java file ex: 'CustomClientFactory' inside directory app > Java > com > (your_app_name) > CustomClientFactory.java

Inside that java file add the following code:

import com.facebook.react.modules.network.OkHttpClientFactory;
import com.facebook.react.modules.network.OkHttpClientFactory;
import com.facebook.react.modules.network.OkHttpClientProvider;
import com.facebook.react.modules.network.ReactCookieJarContainer;

import java.security.cert.CertificateException;
import java.util.ArrayList;

import java.util.List;

import java.util.concurrent.TimeUnit;


import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import okhttp3.CipherSuite;
import okhttp3.ConnectionSpec;
import okhttp3.OkHttpClient;
import okhttp3.TlsVersion;

import static android.content.ContentValues.TAG;

public class CustomClientFactory implements OkHttpClientFactory {
private static final String TAG = "OkHttpClientFactory";
@Override
public OkHttpClient createNewNetworkModuleClient() {
    try {
        // Create a trust manager that does not validate certificate chains
        final TrustManager[] trustAllCerts = new TrustManager[]{
                new X509TrustManager() {
                    @Override
                    public void 
checkClientTrusted(java.security.cert.X509Certificate[] chain, String authType) throws 
CertificateException {
                    }

                    @Override
                    public void 
checkServerTrusted(java.security.cert.X509Certificate[] chain, String authType) throws 
CertificateException {
                    }

                    @Override
                    public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                        return new java.security.cert.X509Certificate[]{};
                    }
                }
        };

        // Install the all-trusting trust manager
        final SSLContext sslContext = SSLContext.getInstance("SSL");
        sslContext.init(null, trustAllCerts, new java.security.SecureRandom());
        // Create an ssl socket factory with our all-trusting manager
        final SSLSocketFactory sslSocketFactory = sslContext.getSocketFactory();



        OkHttpClient.Builder builder = new OkHttpClient.Builder()
                .connectTimeout(0, TimeUnit.MILLISECONDS).readTimeout(0, TimeUnit.MILLISECONDS)
                .writeTimeout(0, TimeUnit.MILLISECONDS).cookieJar(new ReactCookieJarContainer());
        builder.sslSocketFactory(sslSocketFactory, (X509TrustManager) trustAllCerts[0]);
        builder.hostnameVerifier(new HostnameVerifier() {
            @Override
            public boolean verify(String hostname, SSLSession session) {
                return true;
            }
        });

        OkHttpClient okHttpClient = builder.build();
        return okHttpClient;
    } catch (Exception e) {
        Log.e(TAG, e.getMessage());
        throw new RuntimeException(e);
    }
}

}

and inside your MainApplication.java add the following:

 @Override
 public void onCreate() {
 super.onCreate();
 SoLoader.init(this, /* native exopackage */ false);  
 OkHttpClientProvider.setOkHttpClientFactory(new CustomClientFactory()); //add this 
 line.
 } 

Found the above solution from : Similar issue

And it worked fine for me. As per I understand, we write this file to Install the all-trusting trust managers and asking the app to allow 'https' api