static.json

{
    "root": "build/",
    "routes": {
      "/**": "index.html"
    },
      "proxies": {
        "/api/": {
            "origin": "https://${API_APP_NAME}.herokuapp.com/accounts"
        },
        "/accounts/": {
            "origin": "https://dry-plains-18498.herokuapp.com/accounts"
          }
      }
  }