core/homeassistant/components/thread/strings.json

{
  "config": {
    "abort": {
      "already_configured": "[%key:common::config_flow::abort::already_configured_service%]"
    },
    "step": {
      "confirm": {
        "description": "[%key:common::config_flow::description::confirm_setup%]"
      }
    }
  }
}