Registers items with a benefit. This is an eventually consistent operation. Items may take a short time to appear
in Query Pool Definition Items results after the call returns. Uses a partial success model. Items already registered
with the benefit return a per-item error in results.itemMetadata, while new items are added successfully.
Check bulkActionMetadata for overall counts and results for per-item outcomes.
You can only call this method when authenticated as a Wix app or Wix user identity.
There is 1 error with this status code.
This method may also return standard errors. Learn more about standard Wix errors.