We have 000874 which is embargoed and contains zarr. "zarrbargo" was implemented awhile back and this might be the first dandiset which takes advantage of that. ATM backup crashes with

    | RuntimeError: Dandiset 000874 is embargoed and contains a Zarr at derivatives/OCT-pipeline/sub-SP002/micr/sub-SP002_ses-OCT_sample-01_res-20um_OCT.ome.zarr; do not know how to handle     

handling should be similar to embargoed dandisets -- we should prepare private zarr datasets, URLs to zarr files should go through DANDI api and datalad backend for authentication, and whenever unembargoing, change them to public and register direct URLs to S3.