curl --request POST \
  --url https://api.merchantops.ai/api/products/{product_key}/variants/upload-csv \
  --header 'Content-Type: application/json' \
  --data '
{
  "csv_content": "<string>",
  "batch_size": 25
}
'

{
  "created": 123,
  "errors": [
    {}
  ]
}