That should be available on mastodon such that you can donate to your fav people/orgs
This Already exists. You can stick the URL to your Patreon / Ko-Fi / LiberaPay / Venmo / Cashapp / PayPal / Zelle / OnlyFans / WeChat / etc. into your Bio. There's even a convenient grid of listing lots of URLs or other info.
Don't make the mistake of wanting an "everything app". Integrating DeFi into Mastodon itself would be a catastrophe. Let people use the financial tools they already have, instead of trying to create some new banking system built on social media.