Is it possible to use cursors for analytics conversations details query in zapier?

Is it possible to paginate the /api/v2/analytics/conversations/details/query endpoint using cursors instead of page numbers? i am building a custom zapier action and the standard page param seems inefficient for large datasets. the docs mention a cursor field in the response but i keep getting 400 bad request when i pass it back in the next call. here is my json payload:

{"timeInterval": {"startDateTime": "2023-10-01T00:00:00Z", "endDateTime": "2023-10-02T00:00:00Z"}, "viewId": "myView", "cursor": "eyJpZCI6MTIzfQ=="}

why is this failing?