curl --request POST \
  --url https://api.iotools.cloud/v1/tool/bionic-reading-converter \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "text": "Hello World! This is a test.",
  "fixation": "4",
  "textContrast": "medium",
  "highlightColor": "#000000"
}
'

{
  "tool": "bionic-reading-converter",
  "tool_version": "1.0.1",
  "outputs": {
    "output": "<div style=\"color:#858585\"><p><b style=\"color:#000000\">He</b>llo <b style=\"color:#000000\">Wo</b>rld! <b style=\"color:#000000\">Th</b>is <b style=\"color:#000000\">i</b>s a <b style=\"color:#000000\">te</b>st.</p></div>"
  },
  "credits_used": 3,
  "credits_remaining": null
}