When working with a OAI-PMH import profile you must select an existing record set provided from the OAI-PMH provider. Some providers, Datacite as an example, offer the ability to harvest a record set using a query[1] which is not included as a predefined record sets by the ListSets method. The OAI-PMH import profile should offer the ability to select a record set to harvest from a pre-defined list OR provide a record set name not in the list, a query in the case of Datacite.

[1]Bottom of this page: https://support.datacite.org/docs/datacite-oai-pmh