Product activation through web application

Hi, everyone, I'm a new member here.

Currently, I'm developing a web application and there's a need to make an activation for the product I developed. My question is, is it possible to make that? As we know, there are a lot of desktop softwares required activation through internet or by phone (and it seems the softwares write to the registry too) but I never see web application do the same thing. Maybe one of you ever make something like that?

Thanks in advance. Roby.

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