Initiate onramp

curl --request POST \
  --url https://api.privy.io/v1/users/{user_id}/fiat/onramp \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'Content-Type: application/json' \
  --header 'privy-app-id: <privy-app-id>' \
  --data '{
  "amount": "<string>",
  "provider": "bridge",
  "source": {
    "payment_rail": "sepa",
    "currency": "usd"
  },
  "destination": {
    "chain": "ethereum",
    "currency": "usdc",
    "to_address": "<string>"
  }
}'

{
  "id": "<string>",
  "status": "awaiting_funds",
  "deposit_instructions": {
    "amount": "<string>",
    "currency": "usd",
    "payment_rail": "sepa",
    "deposit_message": "<string>",
    "bank_name": "<string>",
    "bank_account_number": "<string>",
    "bank_routing_number": "<string>",
    "bank_beneficiary_name": "<string>",
    "bank_address": "<string>",
    "iban": "<string>",
    "bic": "<string>",
    "account_holder_name": "<string>"
  }
}