I noticed that technically it is already possible to use Revolut as payment method in online stores, but many online stores offer payments trough third parties like Klarna and Paytrail/Nets (at least here in Finland). Most often these services ask you to login into your bank account and the service directly transfers the funds to the recipients. There is also an option to use MobilePay which works by typing your phone number and accepting the payment from the app. It would be very helpful if Revolut was an bank option or an integrated payment processor like MobilePay. Think it like Paypal, but integrated directly to services like Klarna or Paytrail.
This is of course up to the strategy at Revolut, but I think Revolut would gain a lot of new customers, because the current payment options are not that convenient, except MobilePay which is hugely popular because of its ease of use and many student organizations in my university offer it as the only payment option. Revolut business isn’t to my knowledge available as alternative for non profits.