curl -X POST https://api.ledger.so/v1/customers/cus_.../rain-application \
-H "Authorization: Bearer $LEDGER_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: rain-app-1" \
-d '{
"birthDate": "1990-01-01",
"nationalId": "...",
"countryOfIssue": "US",
"address": {
"line1": "123 Main St",
"city": "San Francisco",
"region": "CA",
"postalCode": "94105",
"countryCode": "US"
},
"ipAddress": "203.0.113.10",
"occupation": "...",
"annualSalary": "...",
"accountPurpose": "...",
"expectedMonthlyVolume": "...",
"phoneCountryCode": "+1",
"phoneNumber": "4155550101"
}'