curl --request POST \
  --url https://api.iotools.cloud/v1/tool/error-function-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "mode": "erf",
  "y": "0"
}
'

{
  "tool": "error-function-calculator",
  "tool_version": "1.0.2",
  "outputs": {
    "result": [
      {
        "function": "erf⁻¹(0)",
        "value": "0.00000000"
      },
      {
        "function": "Check: erf(0.00000000)",
        "value": "0.00000000"
      }
    ]
  },
  "credits_used": 5,
  "credits_remaining": null
}