I got an email saying a keylogger was put on my iPhone 11 and taken my passwords

It’s a scam. Don’t respond to it. It’s not possible to install a keylogger on an iOS device unless it is jailbroken. You can forward it to reportphishing@apple.com.

Here’s more information on this type of fraud—>Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams - Apple Support

It is a phishing email. There is no keylogger that will work on a non-jailbroken iPhone. Avoid phishing emails, fake 'virus' alerts, phony support calls, and other scams - Apple Support

No. It's a scam, unless your iPhone is jailbroken.

You should do

1. Settings > Safari > Clear History and Website Data
2. Restart your iPhone - Apple Support

The way he got that one single password of yours was buying it online. Was it one you currently use, or one you used to use? If one you used to use, it would have come from a compromised site, like the Sony PS4 Store, or Yahoo, or any of the other dozens of commercial sites hacked into and passwords stolen from in the past decade or so. Those stolen passwords get passed all around the web, basically to anyone who wants to use them.

And of course, they wanted their ransom in bitcoin, right? This is a very common and very widely circulating phishing scam.

Hi, deggie. GMTA.

And to -finwd, it should be reassuring to get two replies that provide the same answer.

I think this is the first time I've slipped in before you. Kind of scary how close our posts were in language. Good luck to you with social distancing.