curl --request POST \
  --url https://api.withflex.com/v1/disputes/{dispute_id} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "dispute": {
    "evidence": {}
  }
}
'

{
  "dispute": {
    "dispute_id": "<string>",
    "payment_intent_id": "<string>",
    "amount": 123,
    "created_at": "<string>",
    "status": "lost",
    "reason": "<string>",
    "evidence": {}
  }
}