I use the apple notes app with the lock feature for this. And sometimes without the lock feature.

I don’t see that happening tbh, since they made Secure Notes for this purpose which (i would assume they believe) offers a better experience than storing not-logins with logins. Secure Notes offer the same level of security as the keychain IIRC.

Yes, you can create a "New Secure Note Item"

Is this in Passwords or the Notes app?

I tried Notes app with the Lock but it requires another password while I want it all under the FaceID/iCloud password like the settings-passwords

Is there a secure note option in passwords - mine all require username web url and password.

You might have to check your settings. Previously there was a separate password for Notes, but now there is an option to keep it tied to your account's password

it is the Keychain Access app

Oh that’s only on MacOs not iOS, right?

I am pretty sure it is limited to the desktop OS.

Yes, it can. You can store Secure Notes in your keychain with Keychain Access on macOS.