How to send messages from content to background

// in content.tsx
 const resp = await sendToBackground({
    name: "upload-from-url",
    body: {
      url: "https://superlink.com"
    }
  })

  console.log("resp", resp)

// in background/upload-from-url.ts
import type { PlasmoMessaging } from "@plasmohq/messaging"

const handler: PlasmoMessaging.MessageHandler = async (req, res) => {
  const { url } = req.body

  console.log(url)

  res.send("hello world")
}

export default handler