APIM: Public network access disable for Internal Virtual Network Model

I have an Azure APIM that configured with Internal Virtual network mode. I dont have any private endpoint configured because my APIM is already private with the network configuration (internal mode). I could see the `public access` is enabled . I dont know what it means exactly - Does it mean my API deployed inside from APIM or the Gateway URL which i configured with private dns can be accessed public ?

Anyhow just to prevent anything to go public access. I'm trying to change the public access to Disable. But i couldnot able to do that I'm getting the error like below

> Disabling all `publicNetworkAccess` for service: /subscriptions/xxxx/resourceGroups/xxxx/providers/Microsoft.ApiManagement/service/api-mgmt-01 is not supported if the service does not atleast one approved Private Endpoint Connections.
> Code: NotSupported
>

with 400 Bad request

I used azure cli for the updates. Internally the azure cli used the `api-version=2022-08-01`

Start with the Azure CLI update path and the APIM 2022-08-01 API behavior for publicNetworkAccess, then compare the internal virtual network and private endpoint requirements described in the error. Done means establishing whether disabling public access is supported for this configuration and documenting or correcting the reported behavior.

Written by the indexing model from the issue text.