CustomFeedRequestV1

{
    "data": {
        "type": "custom-feed",
        "attributes": {
            "name": "All companies",
            "notifications": [
                {
                    "sending_interval": "day",
                    "medium": "email",
                    "user_id": 12345
                }
            ],
            "advanced_filters": {
                "type": "group",
                "operator": "and",
                "items": [
                    {
                        "type": "filter",
                        "field": "country_code",
                        "operator": "all_are",
                        "value": "string",
                        "display_value": "Germany"
                    }
                ]
            }
        },
        "relationships": {
            "folder": null
        }
    }
}