ESP32 CAM not connecting

[a10pepo]

I am using ESP32 CAM to send images by mqtt to IoT Core in GCP but I am not able to make a connection to the server.
I am using this library:

I have configured ciotc_config.h
I have flashed the esp32_lwmqtt into the ESP32 CAM using arduino ide
And I am getting the following error:

Connecting...
Refreshing JWT
not connected
Settings incorrect or missing a cyper for SSL
Connect with mqtt.2030.ltsapis.goog:8883
ClientId: projects//locations/europe-west1/registries//devices/
Waiting 60 seconds, retry will likely fail

I was able in the past to do this on ESP8266 using certificates but not able to replicate on ESP21 any idea?

On the other side, I have tested using mosquitto_pub and everything connects and send data correctly.. what am I missing?