az eventgrid event-subscription create command error

[mumurug-MSFT]

Related command

az eventgrid system-topic event-subscription create
az eventgrid event-subscription create

Extension name (the extension in question)

az eventgrid

Description of issue (in as much detail as possible)

In Azure Portal, we can create an event subscription for system topic with enabling dead-lettering as shown below: (doc reference)

However, az eventgrid system-topic event-subscription create doesn't have parameters deadletter-identity and deadletter-identity-endpoint in CLI and running results in unrecognized arguments: --deadletter-identity-endpoint /subscriptions/xxx/resourceGroups/xxx/providers/Microsoft.Storage/storageAccounts/xxx/blobServices/default/containers/egcontainer --deadletter-identity systemassigned error.

So followed az eventgrid topic event-subscription create doc and ran the following command and it also resulted in error.
Command:
az eventgrid event-subscription create --name xxx --source-resource-id "/subscriptions/xxx/resourceGroups/xxx/providers/Microsoft.EventGrid/systemTopics/xxx" --endpoint-type storagequeue --endpoint "/subscriptions/xxx/resourceGroups/xxx/providers/Microsoft.Storage/storageAccounts/xxx/queueservices/default/queues/xxx" --deadletter-identity-endpoint "/subscriptions/xxx/resourceGroups/xxx/providers/Microsoft.Storage/storageAccounts/xxx/blobServices/default/containers/egcontainer" --deadletter-identity systemassigned

Output:
Code: InvalidRequest
Message: This event subscription operation is not supported using this API call. Please use the proper API and try again.

Any plan for supporting deadletter-identity for system topic? These parameters are available in both ARM template as well as Rest API.

[yonzhan]

Thank you for opening this issue, we will look into it.

[PramodValavala-MSFT]

@mumurug-MSFT Thanks for the feedback! We will review and get back to you.

[microsoft-github-policy-service]

Thanks for the feedback! We are routing this to the appropriate team for follow-up. cc @jfggdl.