curl --request POST \
  --url https://api.iotools.cloud/v1/tool/geojson-wkt-converter \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "direction": "geojson-to-wkt",
  "input": "{\"type\":\"Polygon\",\"coordinates\":[[[30,10],[40,40],[20,40],[10,20],[30,10]]]}",
  "coordPrecision": "full",
  "uppercase": "true",
  "prettyPrint": "true"
}
'

{
  "tool": "geojson-wkt-converter",
  "tool_version": "1.0.1",
  "outputs": {
    "output": "POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))"
  },
  "credits_used": 3,
  "credits_remaining": null
}