You might ask, Why did they reject you! Ask yourself these questions.
do you have a functional website? a privacy policy? terms and conditions? Faq? contact form? do you have a US business address (not virtual) with a US phone number on your website?. Did you tell them that you will serve US clients/suppliers/businesses...etc.?
If your answer to my above questions is no, then you need to work on your website and business first, then apply to a bank account. Also if you deal with anything related to crypto, then don't look for US neo banks, they have no appetite whatsoever for unregistered crypto businesses, and you better look for other options like Bankera, advcash...etc. who work with crypto-related companies.
Having said that, there are other neo banks like mercury such as:
Relay (Relay Financial), is an all-in-one business banking and money management platform helping businesses understand what they're earning, spending & saving.
relayfi.com
Spend smarter with integrated corporate cards, expenses, travel, and payments — in 100+ countries.
www.brex.com
Modern U.S business banking. All your business financial apps in one place: banking, payouts, cards, invoicing & more!
www.trynovel.com
Make expense management easy with Ramp’s spend management platform. Combine global corporate cards, travel, expenses and accounts payable to automate finance operations and improve efficiency.
ramp.com
(Ramp is more like a corporate card (better than brex in some cases), and not a bank account, for ramp you need to have a business account (any of the above could work), have a 75k in your business account and most of your business spending in the US such as hosting, marketing...etc)
But seriously, you need to work on your business first and then apply for a bank account, otherwise, no neo bank will onboard you and you will have to travel to the US to find a solution.