Just trying to be helpful mate!

How do you know where they live, what their gender is, and what is your problem?

I asked why the “no Internet”:

Literally any answer is correct - it just gives us a better baseline to start giving suggestions. You need to chill out.

I bet you asked your mate what they actually wanted.

Do you know if they want this simply so they don’t have to walk downstairs, or do they want to view it on their phone?

This could be for an apartment they own and they just want to offer their tenants something so they can see who their buzzing in for all we know.

Helpful is figuring out what they want and not blindly going into details on solutions that at best waste their time reading or worse lead then down a suboptimal solution.

What are the reasons for your “no Internet” requirement?

Security concerns? Are you adverse to the idea of WiFi? Do you just not have Internet? Or are you just interested in a single screen on a wall in this house to interface with the doorbell?

Your going to continue to get crap answers unless you specify.