Get a strong random password made on your own device. Nothing is sent over the internet.
Password strength is counted in bits of entropy, and every extra bit doubles the number of guesses an attacker would need. Current guidance looks like this:
Everything happens inside your browser, which draws on the cryptographically secure window.crypto.getRandomValues API. We never receive, log or store the passwords you create. To check, open DevTools, go to the Network tab and generate a few: you will see no requests go out.