I was developing an app which send some receipt to a mobile phone, and I try to use using two Broadcast Receivers, like this:

enter persistSentMessageIfRequired(), mAppInfo.packageName = [******], mPersistMessage = [true] (Ask Gemini)
java.lang.Throwable at com.android.internal.telephony.SMSDispatcher$SmsTracker.persistSentMessageIfRequired(SMSDispatcher.java:1565) at com.android.internal.telephony.SMSDispatcher$SmsTracker.persistOrUpdateMessage(SMSDispatcher.java:1634) 
at com.android.internal.telephony.SMSDispatcher$SmsTracker.onFailed(SMSDispatcher.java:1655) 
at com.android.internal.telephony.SMSDispatcher.sendRawPdu(SMSDispatcher.java:1055) 
at com.android.internal.telephony.gsm.GsmSMSDispatcher.sendText(GsmSMSDispatcher.java:424) 
at com.android.internal.telephony.ImsSMSDispatcher.sendText(ImsSMSDispatcher.java:208) 
at com.android.internal.telephony.IccSmsInterfaceManager.sendTextInternal(IccSmsInterfaceManager.java:466)
at com.android.internal.telephony.IccSmsInterfaceManager.sendText(IccSmsInterfaceManager.java:407)
at com.android.internal.telephony.UiccSmsController.sendTextForSubscriber(UiccSmsController.java:140)
at com.android.internal.telephony.ISms$Stub.onTransact(ISms.java:201)
at android.os.Binder.execTransact(Binder.java:723)

Here is my method sendSMS():

val TAG = "TRACK_SMS_STATUS"

fun sendSMS(activity: Activity, phoneNumber: String, message: String) {
    val send = "SMS_SENT"
    val delivered = "SMS_DELIVERED"

    // Create intents
    val sentIntent = Intent(send)
    val deliveredIntent = Intent(delivered)

    // PendingIntents for sent and delivered
    val sentPI = PendingIntent.getBroadcast(activity, 0, sentIntent, 0)
    val deliveredPI = PendingIntent.getBroadcast(activity, 0, deliveredIntent, 0)

    // Create BroadcastReceiver for sent messages
    val sentReceiver = object : BroadcastReceiver() {
        override fun onReceive(context: Context?, intent: Intent?) {
            when (resultCode) {
                AppCompatActivity.RESULT_OK -> {
                    Log.d(TAG, "SMS sent")
                    toast("SMS sent")
                }

                SmsManager.RESULT_ERROR_GENERIC_FAILURE -> {
                    Log.d(TAG, "Generic failure")
                    toast("Generic failure")
                }

                SmsManager.RESULT_ERROR_NO_SERVICE -> {
                    Log.d(TAG, "No service")
                    toast("No service")
                }

                SmsManager.RESULT_ERROR_NULL_PDU -> {
                    Log.d(TAG, "Null PDU")
                    toast("Null PDU")
                }

                SmsManager.RESULT_ERROR_RADIO_OFF -> {
                    Log.d(TAG, "Radio off")
                    toast("Radio off")
                }
            }
        }
    }

    // Create BroadcastReceiver for delivered messages
    val deliveredReceiver = object : BroadcastReceiver() {
        override fun onReceive(context: Context?, intent: Intent?) {
            when (resultCode) {
                AppCompatActivity.RESULT_OK -> {
                    Log.d(TAG, "SMS delivered")
                    toast("SMS delivered")
                }

                AppCompatActivity.RESULT_CANCELED -> {
                    Log.d(TAG, "SMS not delivered")
                    toast("SMS not delivered")
                }
            }
        }
    }

    // Register the broadcast receivers
    // The constant asked to be added doesn't exist under api levels below 33
    activity.registerReceiver(sentReceiver, IntentFilter(send))
    activity.registerReceiver(deliveredReceiver, IntentFilter(delivered))

    // Send the SMS
    val smsManager = SmsManager.getDefault()
    smsManager.sendTextMessage(phoneNumber, null, message, sentPI, deliveredPI)

    // Unregister the receivers after a delay to ensure they catch the broadcasts
    activity.window.decorView.postDelayed({
        activity.unregisterReceiver(sentReceiver)
        activity.unregisterReceiver(deliveredReceiver)
    }, 5000) // Adjust delay as necessary for your context
}

In the lines where I register the receivers I’m getting this warning:

sentReceiver is missing RECEIVER_EXPORTED or RECEIVER_NOT_EXPORTED flag for unprotected broadcasts registered for SMS_SENT

So to protect the broadcast receivers I create a custom permission in my manifest:

<permission
    android:name="******.SEND_SMS"
    android:protectionLevel="signature" />

It’s weird due to when I using a custom server the sms is sent without issue, but using the receivers rise this error.