Hi @masterelaichi,
Welcome to the repair movement! Always glad to have another person to help us save the world one device at a time.
The fingerprint sensor and power button are a single part, so you'll be replacing both functions at the same time. From what I've seen, the parts are readily available online at places like Amazon, eBay and AliExpress among others. To be strictly correct you'll need to find one that comes in the correct color for your phone, but physically any of them will work; you'll just have a mismatched power button. You can use that to make your phone distinctive if you want; for example you could put a white button on a black phone or pick your favorite color regardless of the color of the rest of the phone. Here are a couple of examples that came up on a cursory search.
[link|https://www.mobilesentrix.com/fingerprint-reader-with-flex-cable-for-samsung-galaxy-a22-5g-a226-2021-gray-109839|Samsung A22 5G Spare Parts|new_window=true]
[link|https://www.injuredgadgets.com/fingerprint-scanner-for-samsung-galaxy-a22-5g-a226-2021-mint/|Fingerprint Scanner for Samsung Galaxy A22 5G (A226 / 2021) (Mint) - Injured Gadgets|new_window=true]
I didn't locate a step-by-step set of instructions like you would find here on iFixit, but there is a YouTube video that seems to be reasonably well done and will show you what you need to do.
[link|https://www.youtube.com/watch?v=oZSjSz-dJKQ|Samsung Galaxy A22 5G Fingerprint Sensor Replacement - YouTube|new_window=true]
You will want to make sure you have new replacement precut adhesive sheets for both the rear panel and the midframe to help with both holding the parts on and keeping liquids out. From personal experience I'd suggest getting a couple of each; it's all too easy to get one of them off by a little so it doesn't fit right, and if that happens you can't usually reposition it; you just end up with a tangled ball of adhesive and have to wait till you reorder before you can finish putting your phone back together. They're usually pretty cheap, so having a backup isn't a bad idea.
And if you feel ambitious, you can always author your own iFixit guide for those who follow in your footsteps. It's pretty easy and there's lots of help available if you run into problems; I should know, I've done about 50 of them myself.
Good luck, and let us know how it goes!