Sounds like Paypal, who is “not a bank”, but who operates on the basis that you must link a bank or interact with a bank to do transactions.

You mentioned you “must” link a bank or interact with a bank. Not in this case.

But you say unbanked people can use it?

Yep, I said that.

How do you get cash loaded onto it?

They can go to any 7-Eleven stores to reload their cash into the app. Some other convenience stores offer such service too.