title: "message": "Key path \"file:///app/storage/oauth-private.key\" does not exist or is not readable" in Laravel 6
body: <p>Getting error in Heroku server when try to login with Laravel passport Api. Migration and key generation every working fine. But working fine locally. </p>
  
  <p>Can anyone help me how to generate this key in heroku server by using : </p>
  
  <pre><code>heroku run php artisan passport:key
  </code></pre>
  
  <p>Thank you for your valuable time.
  Full error message</p>
  
  <pre><code>{
  "message": "Key path \"file:///app/storage/oauth-private.key\" does not exist or is not readable",
  "exception": "LogicException",
  "file": "/app/vendor/league/oauth2-server/src/CryptKey.php",
  "line": 48,
  "trace": [
      {
          "file": "/app/vendor/laravel/passport/src/PassportServiceProvider.php",
          "line": 243,
          "function": "__construct",
          "class": "League\\OAuth2\\Server\\CryptKey",
          "type": "-&gt;"
      },
      {
          "file": "/app/vendor/laravel/passport/src/PassportServiceProvider.php",
          "line": 209,
          "function": "makeCryptKey",
          "class": "Laravel\\Passport\\PassportServiceProvider",
          "type": "-&gt;"
      }
  ]
  </code></pre>
  
  <p>}</p>