How can you access a Storage Account blob container without using an Account Key?
I can access data in Storage Account blobs in Power BI ... but it needs the account Access Key !
Is there some way to access the data using some other authentication approach, i.e. an app registration, service principal, managed identity, whatever ?
You could use Shared Access Signature(SAS) to connect Blob Storage in Power BI. This guide will help you.
If you access blob with Azure AD, it doesn't seem to integrate with Power BI. And there is a .Net code sample about creating a block blob.
Azure AD authenticates the security principal (a user, group, or service principal) running the application. If authentication succeeds, Azure AD returns the access token to the application, and the application can then use the access token to authorize requests to Azure Blob storage or Queue storage.
For more information, the document describes the options that Azure Storage offers for authorizing access to resources.