Thank you in advance.
There's an application form at the bottom of https://hackclub.com/bank/. While we started by only serving teenagers starting organizations, we recently started working with adults too. Some organizations that run on Hack Club Bank now have budgets in the $100,000s.
We operate as a fiscal sponsor (https://en.wikipedia.org/wiki/Fiscal_sponsorship), which is a common practice in nonprofits. So while you'd legally be operating as an independent sub-project of The Hack Foundation, you'd be totally autonomous in your brand and operations (and get the benefits of having us take care of all of the bookkeeping and filings with states and the federal government).
If you have any questions, please feel free to email me at zach (at) hackclub.com.