Hello @Raj Tiwari,
welcome to this moderated Azure community forum.
From as far I have seen (and the Azure Portal supports it) you need to use the 'connection string':
You can however route messages TO and EventHub via the IoT Hub routing option:
There, you can use a managed Identity if the IoT Hub identity is activated:
Check out Azure IoT Hub routing.
Be aware the default event-hub-compatible endpoint turns into a fallback solution when routing is added.
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