I have a separate website running, and I would like paid users on this separate site to have access to private pages that have embedded unity projects. This would be a massive amount of users of varying ages, so it needs to be embedded and easy to access. However, I don't want someone to be able to distribute the URL for free, but setting a project to private wouldn't allow them to view the project (unless they also had an itch account... which is not acceptable for business purposes). What is a way that I can prevent others from viewing through the URL, or distributing the URL? What other security issues need to be dealt with?
Edit: Actually the best solution would probably be to restrict which URL it can be viewed from. What's the best way to do that?