curl --request POST \
  --url https://api.xpaycheckout.com/customer/create \
  --header 'Authorization: Basic <encoded-value>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "customerDetails": {
    "name": "John Doe",
    "email": "john.doe@example.com",
    "contactNumber": "+919123456789"
  }
}
'

{
  "customerId": "cus_Tfd3Jq1tZxPjYVhRQW2r3"
}