Launch Telegram app from my own application

    public boolean isAppAvailable(Context context, String appName) {
        PackageManager pm = context.getPackageManager();
        try {
            pm.getPackageInfo(appName, PackageManager.GET_ACTIVITIES);
            return true;
        } catch (PackageManager.NameNotFoundException e) {
            return false;
        }
    }

final String appName = "org.telegram.messenger";
                final boolean isAppInstalled = isAppAvailable(getApplicationContext(), appName);
                if (isAppInstalled) {
                    Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("https://t.me/joinchat/BSLSdUJkvhEVnDI4lbNw3g"));
                    startActivity(intent);
                } else {
                    String msg = getResources().getString(R.string.telegram_not_installed);
                    Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_LONG).show();
                }

References
https://stackoverflow.com/questions/35721942/how-to-launch-telegram-app-from-my-own-android-application