curl --request POST \
  --url https://api.scalev.com/v3/stores/{store_id}/customers/me/cart/items \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "type": "variant",
  "variant_id": 123,
  "quantity": 1
}
'

{
  "id": 123,
  "item_count": 123,
  "total": "<string>",
  "items": [
    {
      "id": 123,
      "type": "variant",
      "variant_id": 123,
      "bundle_price_option_id": 123,
      "quantity": 2
    }
  ]
}