Search availability [should not] requires segment_filter

According to the API doc, the segment filters is not required but when I actually call the API it is required. I am also not sure where to get the service_variation_id

{
	"errors": [
		{
			"category": "INVALID_REQUEST_ERROR",
			"code": "MISSING_REQUIRED_PARAMETER",
			"detail": "Field must be set.",
			"field": "query.filter.segment_filters"
		}
	]
}