post https://api.sb.spidrsrv.com/v1/achaccount/create
Use the /achaccount/create endpoint to associate an external bank account with a given account. Please note: an ACH account must exist for a customer before they can initiate ACH pushes or pulls to external bank accounts. Use the Create ACH Transfer endpoint to originate an ACH transaction to move funds between a customer account and external bank account linked via this endpoint.
ACH transactions history for a customer can be retrieved via the List ACH Requests endpoint.