Azure Import/Export service supports the following of storage accounts:
Standard General Purpose v2 storage accounts (recommended for most scenarios) Blob Storage accounts General Purpose v1 storage accounts (both Classic or Azure Resource Manager deployments), Azure Import/Export service supports the following storage types:
Import supports Azure Blob storage and Azure File storage
Export supports Azure Blob storage. Azure Files not supported.
Only storage4 can be exported.
Reference:
https://docs.microsoft.com/en-us/azure/storage/common/storage-import-export-requirements