Add screenshots

Author: karengu0

articles/defender-for-iot/device-builders/media/quickstart-upload-firmware-using-python/certs-secrets.png

@@ -29,10 +29,15 @@ This quickstart assumes a basic understanding of Defender for IoT Firmware Analy
     pip install azure-mgmt-iotfirmwaredefense
     pip install azure-identity
     ```
-* [Configure](/azure/azure-web-pubsub/howto-authorize-from-application) the following environment variables:
-    * `AZURE_CLIENT_ID` for Azure client ID
-    * `AZURE_TENANT_ID` for Azure tenant ID
-    * `AZURE_CLIENT_SECRET` for Azure client secret
+* Visit [Authorize your application](/azure/azure-web-pubsub/howto-authorize-from-application) to create an application
+    * Once you've created your application, save your Azure client ID and Azure tenant ID from the **Overview** page:
+    :::image type="content" source="media/quickstart-upload-firmware-using-python/overview-client-id-tenant-id.png" alt-text="Screenshot that shows the Overview page of the application." lightbox="media/quickstart-upload-firmware-using-python/overview-client-id-tenant-id.png":::
+    * Save your Azure client secret from the **Certificates & secrets** page. Be sure to copy the value right away because the Azure client secret will only be shown once.
+    :::image type="content" source="media/quickstart-upload-firmware-using-python/certs-secrets.png" alt-text="Screenshot that shows the Certificates & secrets page of the application." lightbox="media/quickstart-upload-firmware-using-python/certs-secrets.png":::
+    * Configure the following environment variables with the three values that you've saved:
+        * `AZURE_CLIENT_ID` for Azure client ID
+        * `AZURE_TENANT_ID` for Azure tenant ID
+        * `AZURE_CLIENT_SECRET` for Azure client secret
 
     In addition, the Azure subscription ID can be configured with the environment variable `AZURE_SUBSCRIPTION_ID`.