design – How to create an application like ChangEd

Really curious, how did ChangEd create their application? Specifically, I would like to know how you would do with money and transactions. How would you send the money to the student loan providers automatically? How do they create a ChangEd FDIC account and store money there? I know that there are APIs like Plaid that allow you to log in to the user's banking data. So, does ChangEd charge you extra, keep the money and send it your name? Or do they create a bank account for you and encourage you to authorize the transaction when you repay the loan?

The ChangEd founder has answered a few questions about Product Hunt, but the underlying design is still unclear to me. Do I need to partner with the bank or student loan provider or can I create an application of this type?