Testing queries at monday.com I’m unable to get past errors when trying to add column values via mutation.

For example this query

mutation ($columnValues: JSON!) {
create_item (board_id: 123456789
, group_id: “topics”
, item_name: “Item name”
, column_values: $columnValues
)
{id}
}

With these query variables

{
“columnValues”: “{"person":[{"id":12237196,"kind":"person"}]}”
}

Returns this error

{
“error_code”: “ColumnValueException”,
“status_code”: 400,
“error_message”: “change_column_value invalid value”,
“error_data”: {
“column_value”: “[{"id"=>12237196, "kind"=>"person"}]”,
“column_type”: “MultiplePersonColumn”
}
}

Simple text columns work but complex columns like people fail. The user id matches query users(king: non_guests) for example, also the id in the url in monday web interface.

Do you know what am I missing?