curl --request POST \
  --url https://api.iotools.cloud/v1/tool/led-resistor-value-calculator \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "supplyVoltage": "9",
  "ledPreset": "custom",
  "forwardVoltage": "2",
  "forwardCurrent": "20",
  "currentUnit": "mA",
  "ledCount": "1",
  "configuration": "series"
}
'

{
  "tool": "led-resistor-value-calculator",
  "tool_version": "1.0.1",
  "outputs": {
    "recommended": "360 Ω (nearest E24 ≥ required)",
    "resultTable": [
      {
        "property": "Required Resistance",
        "value": "350 Ω"
      },
      {
        "property": "Nearest E12 Value (≥)",
        "value": "390 Ω"
      },
      {
        "property": "Nearest E24 Value (≥)",
        "value": "360 Ω"
      },
      {
        "property": "Power Dissipation",
        "value": "140 mW"
      },
      {
        "property": "Min. Resistor Power Rating",
        "value": "1/2 W"
      },
      {
        "property": "Resistors Needed",
        "value": "1 resistor"
      }
    ],
    "notes": ""
  },
  "credits_used": 3,
  "credits_remaining": null
}