Below error suggests that we need to add "Defender for IOT " or "Azure Security for IoT" as Log Analytics Contributor from the concerned log analytics IAM.
FailedDependency Unable to read Log Analytics workspace /subscriptions/.../providers/microsoft.operationalinsights/workspaces/law-defender-for-iot, please make sure to grant the required permissions to access the Defender for IoT experience..
Please make sure you have followed the steps on access controls and other required steps as mentioned in this document.
Thank you.