Well I googled putty and found a couple different .org domains, one who which said it was legit but not official, and another which said it was official but looked wildly out of date.
Neither one I could find a download for Mac that worked. The one I tried gave a scary “we no longer allow putty sudo access as it’s dangerous” and when I googled this error I could find no explanation to assuage me.
And since I wanted to make sure what I was doing was legit, I searched for alternatives.
Eventually I discovered I could use command line in mac to generate the keys I needed. But first I installed Xcode then ran the command (I used chatgpt to tell me exactly how to get the type and length I needed). It was easy.
Side note, the whole culture of downloading random software and using it with just a single line in a terminal is always sketchy to me too. But I’m not a coder so I’m not used to it.