Hi @dari_donkuro – would you be able to share the ID of the Customer? I can take a look on our end to see what caused the error.
As for retrieving a Customer’s ID, we recommend storing the ID in your DB every time you create a new Customer. Additionally, you can also retrieve a list of Customers in your platform via the API and the Dashboard. Find more information on the API call here in our docs -
https://docs.dwolla.com/#list-and-search-customers