is there a way to disallow the option of password usage when using
navigator.get(options)
or
navigator.create(options)
it's possible to disable the password / pin code when you write a native application (Android)
Short answer: no.
Nearly all authenticators offer some kind of either local PIN or local password for unlocking the authenticator. Biometrics are typically convenience methods.
The only way to change this behavior would be if the authenticator itself offers a configuration option, but that is authenticator level and cannot be influenced via WebAuthn.