You cannot do this with OCI.
We don't model and inventory each individual Ontap snapshot. We should know the snapshot count for flexvols on 7 mode and 8.2.0 and higher cDOT systems. 8.1.0 cDOT support is not possible due to the lack of Ontap ZAPI support to retrieve this information.
There are no plans for OCI to pull this data - it is exceptionally time consuming to pull this information.