curl --request POST \
  --url https://api.linkio.world/otc/onramp \
  --header 'Content-Type: application/json' \
  --header 'ngnc-sec-key: <api-key>' \
  --data '
{
  "customer_id": "<string>",
  "amount": "<string>",
  "wallet_address": "<string>",
  "paymentDetails": {
    "accountNumber": "<string>",
    "routingNumber": "<string>",
    "accountName": "<string>",
    "bankName": "<string>"
  }
}
'

{
  "code": "TXN_SUCCESSFUL",
  "status": "Success",
  "message": "<string>",
  "data": {
    "transaction_id": "<string>",
    "reference": "link-otc-12345678",
    "type": "onramp",
    "currency": "<string>",
    "amount": "<string>",
    "stables": "<string>",
    "payout_amount": "<string>",
    "rate": 123,
    "transaction_status": "pending",
    "payment_method": "<string>",
    "date_created": "<string>"
  }
}