{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "div",
  "children": [
    {
      "elmType": "div",
      "style": {
        "display": "=if(length(@currentField) == 0, 'flex', 'none')",
        "align-items": "center",
        "gap": "10px",
        "padding": "12px",
        "border-left": "4px solid #ffb900",
        "background-color": "#fff4ce",
        "border-radius": "6px"
      },
      "children": [
        {
          "elmType": "span",
          "attributes": {
            "iconName": "Warning"
          },
          "style": {
            "font-size": "20px",
            "color": "#8a6d00"
          }
        },
        {
          "elmType": "div",
          "children": [
            {
              "elmType": "div",
              "txtContent": "Missing information",
              "style": {
                "font-weight": "600"
              }
            },
            {
              "elmType": "div",
              "txtContent": "This field has not been completed.",
              "style": {
                "font-size": "12px",
                "color": "#605e5c"
              }
            }
          ]
        }
      ]
    },
    {
      "elmType": "div",
      "style": {
        "display": "=if(length(@currentField) == 0, 'none', 'block')"
      },
      "txtContent": "@currentField"
    }
  ]
}