Looks like it is unable to find the storage policy being provided (8acc7829-4e1a-447c-9a21-d2ee8235db5a) does not exist.
You can list the available storage profiles in Provider vdc using below API
fetch the provider vdc ID from
GET https://vcd_fqdn/api/admin
GET https://vcd.fqdn/api/admin/providervdc/{id}
and look for section <StorageProfiles>
(OR)
Get the storage profile IDs from database
select * from prov_vdc_logical_resource where lr_type like '%STORAGE%';