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”: “r{"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?