My vercel site accidentally made 404 Not Found error so I added ‘rewrites’ to vercel.json.

{
    "rewrites": [
        {"source": "/(.*)", "destination": "/"}
    ],
    "cleanUrls": true
}

However, I’m not sure it is because of ‘rewrites’, public/404.html is not automatically redirected. It is redirected to index.html. I have tried several methods, but they didn’t work:

{
  "rewrites": [
      { "source": "/(.*)", "destination": "/index.html" }
  ],
  "redirects": [
    {
      "source": "/:path*",
      "destination": "/404.html",
      "statusCode": 404
    }
  ],
  "cleanUrls": true
}

or

{
    "rewrites": [
        { "source": "/404", "destination": "/404.html" },
        {"source": "/(.*)", "destination": "/"}
    ],
        "cleanUrls": true
}

But I also couldn’t fix 404 Not Found error if I didn’t use rewrites.