How to communicate MQTT-TLS from BX3105 to Azure IoT Hub

Hello.
I am using the BX3105 module with firmware version 2.7.2.

I’m trying to use MQTT as TLS in IoT Hub in Microsoft Azure.


Question 1. What should I put in my local certificate?
‘RootCA.cer’ is registered for the root certificate, and ‘N_Device_CACerts_1-private.pem’ is registered for the private certificate. I tried putting ‘N_Device_CACerts_1-public.pem’ as the local certificate, and everything was OK, but it seems that the connection is not normal.

Question 2. Is the MQTT connection command below correct?
AT+KMQTTCFG=1,“AABBCCDD.azure-devices.net”,8883,4,“N_Device_CACerts_1”
or
AT+KMQTTCFG=1,“AABBCCDD.azure-devices.net”,8883,4,“N_Device_CACerts_1”,60,1,1,“devices/N_Device_CACerts_1/messages/%02F”,“off”,0,1,“AABBCCDD.azure-devices.net/N_Device_CACerts_1/Fapi-version=2021-04-12","
(AABBCCDD is my iot hub name)


No matter how hard I try
+KMQTT_IND: 1,6
+KMQTT_IND: 1,0
is returned.

Help.
Thanks in advance for your reply.