{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "div",
  "children": [
    {
      "elmType": "div",
      "style": {
        "display": "=if(@currentField,'','none')",
        "margin-left": "8px",
        "margin-right": "8px"
      },
      "attributes": {
        "class": "ms-fontColor-themePrimary"
      },
      "children": [
        {
          "elmType": "span",
          "txtContent": "@currentField.desc",
          "style": {
            "cursor": "pointer",
            "text-decoration": "underline"
          },
          "attributes": {
            "class": "ms-fontColor-themeDarker--hover ms-fontSize-s",
            "title": "Click to open callout with embedded content."
          },
          "customRowAction": {
            "action": "embed",
            "actionInput": {
              "src": "@currentField",
              "height": "360",
              "width": "640"
            }
          }
        },
        {
          "elmType": "span",
          "style": {
            "padding-left": "3px"
          },
          "attributes": {
            "iconName": "ActionCenter",
            "class": "ms-fontSize-mi"
          }
        }
      ]
    }
  ]
}