core/homeassistant/components/opensky/strings.json

{
  "config": {
    "step": {
      "user": {
        "description": "Fill in the location to track.",
        "data": {
          "radius": "Radius",
          "latitude": "[%key:common::config_flow::data::latitude%]",
          "longitude": "[%key:common::config_flow::data::longitude%]",
          "altitude": "Altitude"
        }
      }
    }
  }
}