When I was looking for a white-label payment solution, there were some compromises everywhere: either the interface could not be branded, or the API was inconvenient, or they simply did not respond. By chance, I came across the recommendation
https://www.padmagazine.co.uk/business-money-legal-jobs/build-it-your-way-why-more-businesses-are-choosing-custom-branded-payment-solutions/28953/ on the forum, decided to try it — and indeed, everything is as described. The platform is very flexible, you can create a payment page completely for yourself, no connection to someone else's brand. Everything is stable and transparent.