Mbed arm, azure, mqtt , tls

Mbed TLS
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i would like to generate a secure connection between the Mbed device and Azure. The communication protocol I’m using is MQTT.i has read the document regarding the connecting using MQTT directly from Understand Azure IoT Hub MQTT support | Microsoft Learn. I have a doubt about the password section.

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Here how will I get the

  1. {signature-string}?
  2. {expiry}?
  3. {URL-encoded-resourceURI}? because I only know the details about the HostName, Device ID, and Sharedaccesskey.