I read about shared access signatures generated with stored access policies for Azure Storage from here.
I also read how to create this shared access signature with stored access policies for Azure Storage using PowerShell here.
However, I want to do the above using Azure Portal. I know how to generate an ad-hoc shared access signature. I also know how to create a stored access policy for a container in my Azure Blob.
How do I create a shared access signature with a stored access policy for an Azure Blob container in Azure Portal?
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.