Alexa is a good place to lock a door by voice and a weak place to manage who can open it. Matter gives Alexa lock and unlock control, the function Amazon's Matter table requires of a lock, while codes, fingerprints and guest access stay largely with the lock maker: the
Yale Smart Lock with Matter feature list gives Alexa a narrower set of access tools than Apple Home or SmartThings. Pick a lock whose own app you are happy to keep for enrollment and visitor codes. Most locks here use Thread, and Amazon says a Thread border router must commission them. An Echo Pop or older Dot is not on Amazon's border router list, so plan on an Echo or eero that is.