unleash.unleash/frontend/vercel.json

{
  "rewrites": [
    {
      "source": "/api/:match*",
      "destination": "https://unleash4.herokuapp.com/api/:match*"
    },
    {
      "source": "/logout",
      "destination": "https://unleash4.herokuapp.com/logout"
    },
    {
      "source": "/auth/:match*",
      "destination": "https://unleash4.herokuapp.com/auth/:match*"
    }
  ]
}