How to create a shared access signature with a stored access policy for an Azure Blob container in Azure Portal?

Preview of Storage Explorer is now available in Azure portal.

You can generate SAS for a container by right clicking on the container and select Get Shared Access Signature like we do in Storage Explorer using the preview

How do I create a shared access signature with a stored access policy for an Azure Blob container in Azure Portal?

Simple answer to your question is that as of today you can't create a shared access signature (SAS) using a stored access policy in Azure Portal. This feature is not there yet. In fact, feature to create a SAS on a blob container is not there on the portal as of yet. You could only create account level SAS using Azure Portal.

If you need to create a SAS on a container using a stored access policy, please use Microsoft Storage Explorer tool (or any other storage explorer tool that has support for blobs management). Using this tool you will be able to specify a stored access policy when creating a SAS on the container.