AT Commands for Connecting to HiveMQ

Hello team, I am working on a project, and I want to send values to MQTT server.
I can’t establish the connection with HiveMQ cluster using GSM Module with AT Commands.
I have managed to send values in the dashboard with the Module , but not in the cluster, which requires authentication.
I also connected to the cluster via the MQTT Dash App in the Smartphone.
Thanks in advance