Need documentation on MiniPay Authentication

[reachjason]

Partners are often curious about this and it's good to have it here

[Edcode-bot]

Hi 👋
I was going through the docs and noticed that MiniPay authentication could benefit from clearer step-by-step guidance for new developers.

I’d be happy to help improve or draft documentation (flows, examples, or diagrams) if this is still needed.
Please let me know the preferred direction or section to start with. Thanks!