Passkeys
How do Passkeys work on sites where you have password already ?
Mac mini 2018 or later
"Since signing in with passkeys uses AutoFill and Face ID or Touch ID for biometric verification, the transition to passkeys is seamless. This lets people use passkeys alongside passwords, so you don’t need to adjust your sign-in page based on credential type. You’ll use the new Authentication Services API to add passkeys, creating sign-in flows that are familiar to users."
There are few videos in the link below that may interest you...
Passkeys Overview - Apple Developer