curl --request POST \
  --url https://api.iotools.cloud/v1/tool/css-email-inliner \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "htmlInput": "<style>p { color: red; }</style><p>Hello</p>",
  "keepUnsupportedRules": "true",
  "removeClassAttrs": ""
}
'

{
  "tool": "css-email-inliner",
  "tool_version": "1.0.1",
  "outputs": {
    "output": "<p style=\"color: red\">Hello</p>"
  },
  "credits_used": 3,
  "credits_remaining": null
}