curl --request PATCH \
  --url https://api.quiva.ai/accounts/payment/subscription \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "items": [
    {
      "id": "si_1234567890",
      "quantity": 2
    }
  ]
}
'

{
  "data": {}
}