You can try this:
````
{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "div",
  "txtContent": "=if([$EndDate]>(@now +259200000), 'GREEN LIGHT', if([$EndDate]>@now && [$EndDate]<= (@now +259200000), 'YELLOW LIGHT', 'RED LIGHT'))",
  "style": {
    "background-color": "=if([$EndDate]>(@now +259200000), 'Green', if([$EndDate]>@now && [$EndDate]<= (@now +259200000), 'Yellow', 'Red'))",
    "color": "black",
    "font-size": "1.5em",
    "justify-content": "center"
  }
}

````
[![enter image description here][1]][1]

Note: In the formula, 86400000 X 3 =259200000

Please refer to [MS Article for Column Formatting][2]


  [1]: https://i.sstatic.net/1hGLe.png
  [2]: https://docs.microsoft.com/en-us/sharepoint/dev/declarative-customization/column-formatting