curl --request PUT \
  --url https://api-eu.flexportal.io/v1/products/{productId} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'Tenant-ID: <tenant-id>' \
  --data '
{
  "productSku": "<string>",
  "name": "<string>",
  "specification": "<string>",
  "category": "<string>",
  "brand": "<string>",
  "variants": [
    {
      "variantSku": "<string>",
      "variantName": "<string>",
      "grade": "<string>",
      "pricing": [
        {
          "contractLength": 2,
          "monthlyPrice": 1,
          "setupFee": 1,
          "discount": {
            "type": "percentage",
            "value": 1,
            "description": "<string>"
          }
        }
      ],
      "colorName": "<string>",
      "rrp": 1
    }
  ]
}
'

{
  "success": true,
  "message": "<string>",
  "productId": "<string>",
  "productSku": "<string>",
  "operation": "created",
  "variantResults": [
    {
      "variantSku": "<string>",
      "operation": "create"
    }
  ]
}