CXone Reporting API: Querying agent state history for last 24 hours

Trying to pull agent state history via CXone Reporting API v2 for the last 24 hours. The docs are sparse on the exact OData filter syntax for time ranges.

GET /api/v2/analytics/reporting/odata/agents/states
?$filter=timestamp ge 2023-10-27T00:00:00Z

Returns 400 Bad Request. Is the date format wrong? Or do I need to use a different endpoint for state history? Using Python requests with a valid Bearer token.