A walkthrough of parameterization of different connection types in Logic App Standard

I am trying to parametrise using system assigned managed identity, in my case for an Azure automation action ... I do this ..

  "azureautomation-Authentication": {
    "type": "Object",
    "value": {
      "type": "ManagedServiceIdentity"
    }
  }

 but when I open the designer I get

I suspect I am missing a value in the parameters to specifically say to use system assigned managed identity, but I have also found an article from an integrator that suggests system assigned managed identity cannot be deployed via code.
Can you advise or provide suggestion?
Thanks

Edit ... of course as soon as I wrote above, I appear (not thoroughly tested) to have resolved my challenge ... so for others ... I added following to my connections.json 

      "connectionProperties": {
        "authentication": {
          "audience": "https://management.core.windows.net/",
          "type": "ManagedServiceIdentity"
        }

 so ...

    "azureautomation": {
      "api": {
        "id": "/subscriptions/@{appsetting('WORKFLOWS_SUBSCRIPTION_ID')}/providers/Microsoft.Web/locations/@{appsetting('WORKFLOWS_LOCATION_NAME')}/managedApis/azureautomation"
      },
      "connection": {
        "id": "/subscriptions/@{appsetting('WORKFLOWS_SUBSCRIPTION_ID')}/resourceGroups/@{appsetting('WORKFLOWS_RESOURCE_GROUP_NAME')}/providers/Microsoft.Web/connections/api_logic_msi_to_azureautomation"
      },
      "connectionRuntimeUrl": "@parameters('azureautomation-ConnectionRuntimeUrl')",
      "authentication": "@parameters('azureautomation-Authentication')",
      "connectionProperties": {
        "authentication": {
          "audience": "https://management.core.windows.net/",
          "type": "ManagedServiceIdentity"
        }
      }
    }