const options = {
  method: 'GET',
  headers: {
    'x-api-key': '<api-key>',
    'x-api-secret': '<api-key>',
    'x-connector-id': '<api-key>',
    'x-owner-id': '<api-key>',
    'x-session-token': '<api-key>'
  }
};

fetch('https://api.runmorph.dev/v1/models/{modelId}/fields', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

{
  "data": [
    {
      "key": "<string>",
      "name": "<string>",
      "type": "text",
      "description": "<string>",
      "format": "<string>",
      "unit": "<string>",
      "optionSource": "<string>",
      "options": [
        {
          "value": "<string>",
          "name": "<string>"
        }
      ],
      "isRequired": true,
      "isFieldReadOnly": true,
      "isValueReadOnly": true,
      "isCustom": true,
      "remote": {
        "key": "<string>",
        "metadata": {}
      }
    }
  ],
  "next": "<string>"
}