How is it possible to do USSD requests on Android?

Ussd api was added in API26.
So since Oreo working with ussd looks smt like this:

    TelephonyManager manager = (TelephonyManager)getSystemService(TELEPHONY_SERVICE);
    manager.sendUssdRequest("*100#", new TelephonyManager.UssdResponseCallback() {
        @Override
        public void onReceiveUssdResponse(TelephonyManager telephonyManager, String request, CharSequence response) {
            super.onReceiveUssdResponse(telephonyManager, request, response);
        }

        @Override
        public void onReceiveUssdResponseFailed(TelephonyManager telephonyManager, String request, int failureCode) {
            super.onReceiveUssdResponseFailed(telephonyManager, request, failureCode);
        }
    }, new Handler());

    TelephonyManager manager2 = manager.createForSubscriptionId(subIdForSecondSlotFromSubscriptonManager);
    manager2.sendUssdRequest(...);

To get the simIDs, you can use the below:

    SubscriptionManager subscriptionManager = (SubscriptionManager) getSystemService(Context.TELEPHONY_SUBSCRIPTION_SERVICE);

    List<SubscriptionInfo> subscriptionInfoList = subscriptionManager.getActiveSubscriptionInfoList();

    for (SubscriptionInfo subscriptionInfo : subscriptionInfoList) {
        int subscriptionId = subscriptionInfo.getSubscriptionId();
        Log.d("Sims", "subscriptionId:" + subscriptionId);
    }

    if (subscriptionInfoList != null) {
        if (subscriptionInfoList.size() == 1) {
            sim1 = subscriptionInfoList.get(0).getDisplayName().toString();
            tvSim1.setText(sim1);
        } else {
            sim1 = subscriptionInfoList.get(0).getDisplayName().toString();
            sim2 = subscriptionInfoList.get(1).getDisplayName().toString();

            tvSim1.setText(sim1);
            tvSim2.setText(sim2);
        }

    }